31:
190:
417:, it is still possible to enhance (or "re-face") them. Most development often goes into adding new interfaces to a legacy system. The most prominent technique is to provide a Web-based interface to a terminal-based mainframe application. This may reduce staff productivity due to slower response times and slower mouse-based operator actions, yet it is often seen as an "upgrade", because the interface style is familiar to unskilled users and is easy for them to use. John McCormick discusses such strategies that involve
1314:
689:. These techniques allow organizations to understand their existing code assets (using discovery tools), provide new user and application interfaces to existing code, improve workflow, contain costs, minimize risk, and enjoy classic qualities of service (near 100% uptime, security, scalability, etc.).
495:
Additionally, the entire Space
Shuttle system, including ground and launch vehicle assets, was designed to work together as a closed system. Since the specifications did not change, all of the certified systems and components performed well in the roles for which they were designed. Even before the
388:
Due to the fact that most legacy programmers are entering retirement age and the number of young engineers replacing them is very small, there is an alarming shortage of available workforce. This in turn results in difficulty in maintaining legacy systems, as well as an increase in costs of procuring
216:
While this term may indicate that some engineers may feel that a system is out of date, a legacy system can continue to be used for a variety of reasons. It may simply be that the system still provides for the users' needs. In addition, the decision to keep an old system may be influenced by economic
485:
program used a large amount of 1970s-era technology. Replacement was cost-prohibitive because of the expensive requirement for flight certification. The original hardware completed the expensive integration and certification requirement for flight, but any new equipment would have had to go through
476:
Andreas M. Hein researched the use of legacy systems in space exploration at the
Technical University of Munich. According to Hein, legacy systems are attractive for reuse if an organization has the capabilities for verification, validation, testing, and operational history. These capabilities must
380:
Integration with newer systems may also be difficult because new software may use completely different technologies. Integration across technology is quite common in computing, but integration between newer technologies and substantially older ones is not common. There may simply not be sufficient
376:
Legacy systems may have vulnerabilities in older operating systems or applications due to lack of security patches being available or applied. There can also be production configurations that cause security problems. These issues can put the legacy system at risk of being compromised by attackers or
570:
A "legacy" product may be a product that is no longer sold, has lost substantial market share, or is a version of a product that is not current. A legacy product may have some advantage over a modern product making it appealing for customers to keep it around. A product is only truly "obsolete" if
384:
Budgetary constraints often lead corporations to not address the need of replacement or migration of a legacy system. However, companies often don't consider the increasing supportability costs (people, software and hardware, all mentioned above) and do not take into consideration the enormous loss
368:
These systems can be hard to maintain, improve, and expand because there is a general lack of understanding of the system; the staff who were experts on it have retired or forgotten what they knew about it, and staff who entered the field after it became "legacy" never learned about it in the first
542:
Ginny Hendry characterized creation of code as a `challenge` to current coders to create code that is "like other legacies in our lives—like the antiques, heirlooms, and stories that are cherished and lovingly passed down from one generation to the next. What if legacy code was something we took
696:
from the start, to avoid costly and risky rewrites. The most common legacy systems tend to be those which embraced well-known IT architectural principles, with careful planning and strict methodology during implementation. Poorly designed systems often don't last, both because they wear out and
212:
to describe computer systems probably occurred in the 1960s. By the 1980s it was commonly used to refer to existing computer systems to distinguish them from the design and implementation of new systems. Legacy was often heard during a conversion process, for example, when moving data from the
100:, where changes to the runtime environment, or surrounding software or hardware may require maintenance or emulation of some kind to keep working. Legacy code may be present to support legacy hardware, a separate legacy system, or a legacy customer using an old feature or software version.
1025:
Menychtas, Andreas; Konstanteli, Kleopatra; Alonso, Juncal; Orue-Echevarria, Leire; Gorronogoitia, Jesus; Kousiouris, George; Santzaridou, Christina; Bruneliere, Hugo; Pellens, Bram; Stuer, Peter; Strauss, Oliver; Senkova, Tatiana; Varvarigou, Theodora (2014), "Software modernization and
582:. A software product that is capable of performing as though it were a previous version of itself, is said to be "running in legacy mode". This kind of feature is common in operating systems and internet browsers, where many applications depend on these underlying components.
477:
be integrated into various software life cycle phases such as development, implementation, usage, or maintenance. For software systems, the capability to use and maintain the system are crucial. Otherwise the system will become less and less understandable and maintainable.
62:, "of, relating to, or being a previous or outdated computer system", yet still in use. Often referencing a system as "legacy" means that it paved the way for the standards that would follow it. This can also imply that the system is out of date or in need of replacement.
424:
Printing improvements are problematic because legacy software systems often add no formatting instructions, or they use protocols that are not usable in modern PC/Windows printers. A print server can be used to intercept the data and translate it to a more modern code.
486:
that entire process again. This long and detailed process required extensive tests of the new components in their new configurations before a single unit could be used in the Space
Shuttle program. Thus any new system that started the certification process becomes a
385:
of capability or business continuity if the legacy system were to fail. Once these considerations are well understood, then based on the proven ROI of a new, more secure, updated technology stack platform is not as costly as the alternative—and the budget is found.
30:
248:
Even if a legacy system is no longer used, it may continue to impact the organization due to its historical role. Historic data may not have been converted into the new system format and may exist within the new system with the use of a customized
450:
The change being undertaken in some organizations is to switch to automated business process (ABP) software which generates complete systems. These systems can then interface to the organizations' legacy systems and use them as
336:" security vulnerabilities and leaves end users dependent on the good faith and honesty of the vendor providing the updates. This problem is especially acute when these secondary functions of a newer system cannot be disabled.
317:
The way that the system works is not well understood. Such a situation can occur when the designers of the system have left the organization, and the system has either not been fully documented or documentation has been
480:
According to Hein, verification, validation, testing, and operational history increases the confidence in a system's reliability and quality. However, accumulating this history is often expensive. NASA's now retired
455:. This approach can provide a number of significant benefits: the users are insulated from the inefficiencies of their legacy systems, and the changes can be incorporated quickly and easily in the ABP software.
265:
can be significant. A legacy system may include procedures or terminology which are no longer relevant in the current context, and may hinder or confuse understanding of the methods or technologies used.
606:
technology is a recent innovation allowing legacy systems to continue to operate on modern hardware by running older operating systems and browsers on a software system that emulates legacy hardware.
496:
Shuttle was scheduled to be retired in 2010, NASA found it advantageous to keep using many pieces of 1970s technology rather than to upgrade those systems and recertify the new components.
84:
and patterns that are no longer considered modern, increasing the mental burden and ramp-up time for software engineers who work on the codebase. Legacy code may have zero or insufficient
697:
because their inherent faults invite replacement. Thus, many organizations are rediscovering the value of both their legacy systems and the theoretical underpinnings of those systems.
563:
with "legacy support" can detect and use older hardware. The term may also be used to refer to a business function; e.g. a software or hardware vendor that is supporting, or providing
290:, so it cannot be taken out of service, and the cost of designing a new system with a similar availability level is high. Examples include systems to handle customers' accounts in
681:
The IT industry is responding with "legacy modernization" and "legacy transformation": refurbishing existing business logic with new user interfaces, sometimes using
373:
airline company fired its CEO in 2004 due to the failure of an antiquated legacy crew scheduling system that ran into a limitation not known to anyone in the company.
381:
demand for integration technology to be developed. Some of this "glue" code is occasionally developed by vendors and enthusiasts of particular legacy technologies.
646:
There is an alternate favorable opinion—growing since the end of the Dotcom bubble in 1999—that legacy systems are simply computer systems in working use:
392:
Some legacy systems have a hard limit on their total capacity which may not be enough for today's needs, for example the 4 GB memory limit on many older
283:
Retraining on a new system would be costly in lost time and money, compared to the anticipated appreciable benefits of replacing it (which may be zero).
189:
670:
is about five times that of reuse, even discounting the risk of system failures and security breaches. Ideally, businesses would never have to
418:
883:
516:. Eli Lopian, CEO of Typemock, has defined it as "code that developers are afraid to change". Michael Feathers introduced a definition of
357:, the cost of maintaining the system may eventually outweigh the cost of replacing both the software and hardware unless some form of
1135:
929:
825:
903:
692:
This trend also invites reflection on what makes legacy systems so durable. Technologists are relearning the importance of sound
1169:
888:
508:
prefer to describe "legacy code" without the connotation of being obsolete. Among the most prevalent neutral conceptions are
1344:
1149:
295:
1249:
1233:
324:
Newer systems perform undesirable (especially for individual or non-institutional users) secondary functions such as
559:
is often used in conjunction with legacy systems. The term may refer to a feature of modern software. For example,
1190:
1318:
1299:
1209:
951:
1339:
1094:, 6th International Systems & Concurrent Engineering for Space Applications Conference 2014, ESA, p. 3
620:
from the construction industry, where previously developed land (often polluted and abandoned) is described as
458:
198:
1288:
72:
that is no longer supported on standard hardware and environments, and is a codebase that is in some respect
1334:
397:
345:
Legacy systems are considered to be potentially problematic by some software engineers for several reasons.
436:
Biometric security measures are difficult to implement on legacy systems. A workable solution is to use a
1266:
Bisbal, J.; Lawless, D.; Wu, B.; Grimson, J. (1999). "Legacy
Information Systems: Issues and Directions".
707:
579:
452:
414:
370:
362:
230:
637:
is an upgrade or addition to an existing software or network architecture that retains legacy components.
693:
671:
600:
are more difficult to place into legacy mode as they include many components making up a single system.
597:
532:
262:
258:
81:
524:, which reflects the perspective of legacy code being difficult to work with in part due to a lack of
433:
documents may be created in the legacy application and then interpreted at a PC before being printed.
1239:
757:
752:
564:
505:
333:
218:
115:
59:
1060:, 6th International Systems & Concurrent Engineering for Space Applications Conference 2014, ESA
1001:
465:
461:
307:
299:
108:
586:
528:
242:
238:
174:
135:
123:
77:
39:
589:
era saw many applications running in legacy mode. In the modern business computing environment,
1131:
831:
821:
572:
525:
354:
277:
226:
447:
to sit between users and the mainframe to implement secure access to the legacy application.
1275:
1035:
772:
767:
762:
727:
560:
426:
250:
201:
76:
or supporting something obsolete. Legacy code may be written in programming languages, use
732:
682:
659:
615:
603:
150:
112:
55:
1074:
Heritage
Technologies in Space Programs - Assessment Methodology and Statistical Analysis
930:"Comair's Christmas Disaster: Bound To Fail - CIO.com - Business Technology Leadership"
747:
737:
717:
667:
254:
222:
1259:
820:. Upper Saddle River, NJ: Prentice Hall Professional Technical Reference. p. 15.
276:
The costs of redesigning or replacing the system are prohibitive because it is large,
1328:
1072:
482:
887: prior to 1 November 2008 and incorporated under the "relicensing" terms of the
321:
The user expects that the system can easily be replaced when this becomes necessary.
793:
712:
444:
287:
97:
93:
85:
17:
1106:
742:
722:
686:
651:
269:
Organizations can have compelling reasons for keeping a legacy system, such as:
234:
170:
166:
146:
89:
69:
654:" often differs from its suggested alternative by actually working and scaling.
631:
is a type of software or network architecture that incorporates legacy systems.
1077:, PhD thesis Faculty of Mechanical Engineering, Technical University of Munich
430:
303:
194:
131:
104:
835:
1040:
47:
38:
was still used in some enterprises to run legacy applications, such as this
1313:
815:
575:—if no person making a rational decision would choose to acquire it new.
488:
413:
Where it is impossible to replace legacy systems through the practice of
358:
350:
73:
850:
107:
code that no longer runs on a later version of a system, or requires a
1279:
1026:
cloudification using the ARTIST migration methodology and framework",
955:
594:
590:
437:
178:
35:
468:
approaches can be also used for the improvement of legacy software.
1089:
1055:
878:
103:
While the term usually refers to source code, it can also apply to
976:
188:
127:
119:
29:
273:
The system works well, and the owner sees no reason to change it.
1236:
SECESA 2014, 08-10 October 2014, University of
Stuttgart Germany
1191:"Cost Considerations For A Mainframe to Cloud Migration Project"
441:
401:
311:
291:
162:
1234:
A.M. Hein, How to Assess
Heritage Systems in the Early Phases?
393:
369:
place. This can be worsened by lack or loss of documentation.
904:"Legacy systems continue to have a place in the enterprise"
514:
source code inherited from an older version of the software
149:
like PS/2 and VGA ports, and CPUs with older, incompatible
310:, military defense installations, and systems such as the
229:, or a variety of other reasons other than functionality.
233:(such as the ability of newer systems to handle legacy
27:
Old computing technology or system that remains in use
492:
legacy system by the time it is approved for flight.
1210:"A Survey of Legacy System Modernization Approaches"
1170:"Definition of greenfield and brownfield deployment"
578:
The term "legacy mode" often refers specifically to
1091:
How to Assess
Heritage Systems in the Early Phases?
1057:
How to Assess
Heritage Systems in the Early Phases?
193:Although it has been unsupported since April 2014,
328:) tracking and reporting of user activity and/or
153:(with e.g. newer operating systems). Examples in
666:IT analysts estimate that the cost of replacing
648:
877:This article is based on material taken from
8:
1250:"Comair's Christmas Disaster: Bound To Fail"
1172:. Searchunifiedcommunications.techtarget.com
197:has endured continued use in fields such as
1028:Scalable Computing: Practice and Experience
365:allows the software to run on new hardware.
1039:
111:to do so. An example would be a classic
867:(for example, see Bisbal et al., 1999).
785:
510:source code inherited from someone else
409:Improvements on legacy software systems
1208:Comella-Dorda, Santiago (2000-04-01).
1289:"Legacy Systems: Why History Matters"
1260:"The Failure of the Digital Computer"
1240:"Tips and Tricks for Legacy Hardware"
977:"Benefits of Mainframe Modernization"
173:, and text files encoded with legacy
7:
1128:Working Effectively with Legacy Code
884:Free On-line Dictionary of Computing
817:Working effectively with legacy code
96:. Long-lived code is susceptible to
954:. Mousesecurity.com. Archived from
685:and service-enabled access through
614:Programmers have borrowed the term
332:) automatic updating that creates "
1150:"Take Pride in Your Legacy (Code)"
341:Problems posed by legacy computing
286:The system requires near-constant
92:dangerous and likely to introduce
25:
660:Bjarne Stroustrup, creator of C++
213:legacy system to a new database.
1312:
257:. In either case, the effect on
1302:by Steve R. Smith, May 3, 2011.
928:Stephanie Overby (2005-05-01).
118:which will not run natively on
80:and external libraries, or use
42:food service management system.
1300:"The Danger of Legacy Systems"
1000:McCormick, John (2000-06-02).
952:"The Danger of Legacy Systems"
54:is an old method, technology,
1:
814:Feathers, Michael C. (2005).
296:computer reservations systems
245:often include in their work.
225:, the inherent challenges of
1148:Ginny Hendry (11 Jul 2014).
1105:Lopian, Eli (May 15, 2018).
678:is a perennial requirement.
547:Additional uses of the term
500:Perspectives on legacy code
1361:
1293:Enterprise Systems Journal
1002:"Mainframe-web middleware"
674:most core business logic:
208:The first use of the term
950:Razermouse (2011-05-03).
253:, or may exist only in a
1287:Jim McGee (2005-11-10).
902:Lamb, John (June 2008).
389:experienced programmers.
353:runs on only antiquated
1244:Control Design Magazine
1041:10.12694/scpe.v15i2.980
891:, version 1.3 or later.
629:Brownfield architecture
610:Brownfield architecture
398:4 billion address limit
377:knowledgeable insiders.
302:, energy distribution (
130:application running on
1107:"Defining Legacy Code"
708:Application retirement
664:
580:backward compatibility
573:an advantage to nobody
567:, for older products.
533:characterization tests
427:Rich Text Format (RTF)
415:application retirement
363:backward compatibility
231:Backward compatibility
205:
122:, but runs inside the
43:
1252:by Stephanie Overby,
635:Brownfield deployment
263:operational reporting
259:business intelligence
192:
33:
1345:Technological change
1321:at Wikimedia Commons
1262:by Adam N. Rosenberg
1242:by Danny Budzinski,
758:Software brittleness
753:Software archaeology
565:software maintenance
506:software engineering
308:nuclear power plants
219:return on investment
1217:SEI Digital Library
466:forward engineering
300:air traffic control
243:software developers
239:character encodings
175:character encodings
159:legacy file formats
124:Classic environment
109:compatibility layer
60:application program
18:Legacy applications
1126:Michael Feathers'
1088:A.M. Hein (2014),
1071:A.M. Hein (2016),
1054:A.M. Hein (2014),
587:computer mainframe
531:. He also defined
522:code without tests
206:
136:Windows on Windows
44:
1317:Media related to
1280:10.1109/52.795108
981:Modernization Hub
958:on March 23, 2012
794:"Merriam-Webster"
561:Operating systems
535:to start putting
453:data repositories
280:, and/or complex.
241:) is a goal that
227:change management
16:(Redirected from
1352:
1316:
1296:
1283:
1221:
1220:
1214:
1205:
1199:
1198:
1187:
1181:
1180:
1178:
1177:
1166:
1160:
1159:
1157:
1156:
1145:
1139:
1124:
1118:
1117:
1115:
1113:
1102:
1096:
1095:
1085:
1079:
1078:
1068:
1062:
1061:
1051:
1045:
1044:
1043:
1022:
1016:
1015:
1013:
1012:
997:
991:
990:
988:
987:
973:
967:
966:
964:
963:
947:
941:
940:
938:
937:
925:
919:
918:
916:
914:
899:
893:
892:
874:
868:
865:
859:
858:
846:
840:
839:
811:
805:
804:
802:
800:
790:
773:Vintage computer
768:Stovepipe system
763:Software entropy
728:Digital dark age
676:debits = credits
662:
642:Alternative view
529:regression tests
251:schema crosswalk
217:reasons such as
202:operating system
151:instruction sets
68:is old computer
21:
1360:
1359:
1355:
1354:
1353:
1351:
1350:
1349:
1340:Legacy hardware
1325:
1324:
1309:
1286:
1265:
1230:
1228:Further reading
1225:
1224:
1212:
1207:
1206:
1202:
1195:Kumaran Systems
1189:
1188:
1184:
1175:
1173:
1168:
1167:
1163:
1154:
1152:
1147:
1146:
1142:
1125:
1121:
1111:
1109:
1104:
1103:
1099:
1087:
1086:
1082:
1070:
1069:
1065:
1053:
1052:
1048:
1024:
1023:
1019:
1010:
1008:
999:
998:
994:
985:
983:
975:
974:
970:
961:
959:
949:
948:
944:
935:
933:
927:
926:
922:
912:
910:
908:Computer Weekly
901:
900:
896:
876:
875:
871:
866:
862:
851:"Legacy System"
848:
847:
843:
828:
813:
812:
808:
798:
796:
792:
791:
787:
782:
777:
733:Legacy encoding
703:
683:screen scraping
663:
658:
644:
612:
553:
502:
474:
411:
343:
187:
155:legacy software
143:legacy hardware
138:feature in XP.
86:automated tests
56:computer system
28:
23:
22:
15:
12:
11:
5:
1358:
1356:
1348:
1347:
1342:
1337:
1335:Legacy systems
1327:
1326:
1323:
1322:
1319:Legacy systems
1308:
1307:External links
1305:
1304:
1303:
1297:
1284:
1274:(5): 103–111.
1263:
1257:
1247:
1246:, January 2011
1237:
1229:
1226:
1223:
1222:
1200:
1182:
1161:
1140:
1119:
1097:
1080:
1063:
1046:
1017:
992:
968:
942:
920:
894:
869:
860:
849:Tawde, Swati.
841:
826:
806:
784:
783:
781:
778:
776:
775:
770:
765:
760:
755:
750:
748:Retrocomputing
745:
740:
738:Legacy-free PC
735:
730:
725:
720:
718:Data migration
715:
710:
704:
702:
699:
668:business logic
656:
643:
640:
639:
638:
632:
611:
608:
604:Virtualization
557:legacy support
552:
545:
501:
498:
473:
470:
410:
407:
406:
405:
390:
386:
382:
378:
374:
366:
342:
339:
338:
337:
322:
319:
315:
284:
281:
274:
255:data warehouse
223:vendor lock-in
221:challenges or
186:
183:
141:An example of
26:
24:
14:
13:
10:
9:
6:
4:
3:
2:
1357:
1346:
1343:
1341:
1338:
1336:
1333:
1332:
1330:
1320:
1315:
1311:
1310:
1306:
1301:
1298:
1294:
1290:
1285:
1281:
1277:
1273:
1269:
1268:IEEE Software
1264:
1261:
1258:
1256:, May 1, 2005
1255:
1251:
1248:
1245:
1241:
1238:
1235:
1232:
1231:
1227:
1218:
1211:
1204:
1201:
1196:
1192:
1186:
1183:
1171:
1165:
1162:
1151:
1144:
1141:
1137:
1136:0-13-117705-2
1133:
1129:
1123:
1120:
1108:
1101:
1098:
1093:
1092:
1084:
1081:
1076:
1075:
1067:
1064:
1059:
1058:
1050:
1047:
1042:
1037:
1033:
1029:
1021:
1018:
1007:
1003:
996:
993:
982:
978:
972:
969:
957:
953:
946:
943:
931:
924:
921:
909:
905:
898:
895:
890:
886:
885:
880:
879:Legacy+system
873:
870:
864:
861:
856:
852:
845:
842:
837:
833:
829:
827:0-13-293174-5
823:
819:
818:
810:
807:
795:
789:
786:
779:
774:
771:
769:
766:
764:
761:
759:
756:
754:
751:
749:
746:
744:
741:
739:
736:
734:
731:
729:
726:
724:
721:
719:
716:
714:
711:
709:
706:
705:
700:
698:
695:
690:
688:
684:
679:
677:
673:
669:
661:
655:
653:
647:
641:
636:
633:
630:
627:
626:
625:
623:
619:
618:
609:
607:
605:
601:
599:
598:architectures
596:
592:
588:
583:
581:
576:
574:
568:
566:
562:
558:
550:
546:
544:
540:
538:
534:
530:
527:
523:
519:
515:
511:
507:
499:
497:
493:
491:
490:
484:
483:Space Shuttle
478:
471:
469:
467:
463:
460:
456:
454:
448:
446:
443:
439:
434:
432:
428:
422:
420:
416:
408:
403:
399:
396:CPUs, or the
395:
391:
387:
383:
379:
375:
372:
367:
364:
360:
356:
352:
348:
347:
346:
340:
335:
331:
327:
323:
320:
316:
313:
309:
305:
301:
297:
293:
289:
285:
282:
279:
275:
272:
271:
270:
267:
264:
260:
256:
252:
246:
244:
240:
236:
232:
228:
224:
220:
214:
211:
203:
200:
196:
191:
184:
182:
180:
176:
172:
168:
164:
160:
156:
152:
148:
144:
139:
137:
133:
129:
125:
121:
117:
114:
110:
106:
101:
99:
95:
91:
87:
83:
79:
75:
71:
67:
63:
61:
57:
53:
52:legacy system
49:
41:
37:
32:
19:
1292:
1271:
1267:
1254:CIO Magazine
1253:
1243:
1216:
1203:
1194:
1185:
1174:. Retrieved
1164:
1153:. Retrieved
1143:
1127:
1122:
1110:. Retrieved
1100:
1090:
1083:
1073:
1066:
1056:
1049:
1031:
1027:
1020:
1009:. Retrieved
1005:
995:
984:. Retrieved
980:
971:
960:. Retrieved
956:the original
945:
934:. Retrieved
923:
911:. Retrieved
907:
897:
882:
872:
863:
854:
844:
816:
809:
797:. Retrieved
788:
713:Software rot
694:architecture
691:
687:web services
680:
675:
665:
649:
645:
634:
628:
621:
616:
613:
602:
584:
577:
569:
556:
554:
551:in computing
548:
543:pride in?".
541:
539:under test.
536:
521:
517:
513:
509:
504:Some in the
503:
494:
487:
479:
475:
472:NASA example
459:Model-driven
457:
449:
445:proxy server
435:
423:
412:
344:
329:
325:
288:availability
268:
247:
235:file formats
215:
209:
207:
169:or .123 for
158:
154:
147:legacy ports
142:
140:
102:
98:software rot
82:architecture
65:
64:
51:
45:
743:Legacy port
723:Deprecation
652:Legacy code
537:legacy code
518:legacy code
304:power grids
171:Lotus 1-2-3
167:Adobe Flash
116:application
90:refactoring
70:source code
66:Legacy code
1329:Categories
1176:2012-04-29
1155:2021-10-07
1011:2012-04-29
986:2017-08-23
962:2012-04-29
936:2012-04-29
913:27 October
780:References
622:brownfield
617:brownfield
431:PostScript
419:middleware
349:If legacy
278:monolithic
195:Windows XP
134:using the
132:Windows XP
105:executable
78:frameworks
932:. CIO.com
836:660166658
555:The term
526:automated
359:emulation
334:back-door
314:database.
204:software.
113:Macintosh
88:, making
48:computing
34:In 2011,
1112:June 10,
799:June 22,
701:See also
657:—
489:de facto
355:hardware
351:software
185:Overview
157:include
74:obsolete
1006:Gcn.com
881:at the
672:rewrite
571:it has
462:reverse
126:, or a
40:US Navy
1134:
855:educba
834:
824:
595:3-tier
591:n-tier
549:Legacy
438:Telnet
371:Comair
210:legacy
179:EBCDIC
36:MS-DOS
1213:(PDF)
1034:(2),
593:, or
318:lost.
292:banks
177:like
161:like
128:Win16
120:macOS
58:, or
1132:ISBN
1114:2019
915:2014
889:GFDL
832:OCLC
822:ISBN
801:2013
585:The
512:and
464:and
442:HTTP
402:IPv4
312:TOPS
261:and
237:and
165:for
163:.swf
145:are
94:bugs
50:, a
1276:doi
1036:doi
520:as
440:or
429:or
400:in
394:x86
361:or
306:),
199:ATM
46:In
1331::
1291:.
1272:16
1270:.
1215:.
1193:.
1032:15
1030:,
1004:.
979:.
906:.
853:.
830:.
624:.
421:.
298:,
294:,
181:.
1295:.
1282:.
1278::
1219:.
1197:.
1179:.
1158:.
1138:)
1130:(
1116:.
1038::
1014:.
989:.
965:.
939:.
917:.
857:.
838:.
803:.
650:"
404:.
330:b
326:a
20:)
Text is available under the Creative Commons Attribution-ShareAlike License. Additional terms may apply.
