1. U/FTP (Unshielded Foiled Twisted Pair)

2. UAPITA (You’re a pain in the ass)

3. UART (Universal Asynchronous Receiver/Transmitter)

4. UBE (Unsolicited Bulk E-mail)

5. ubiquitous computing

6. UBR (Unspecified Bit Rate)

7. Ubuntu

8. UCC (Uniform Code Council)

9. UCD (User-Centered Design)

10. UCE (Unsolicited Commercial E-mail)

11. UCP (Universal Communications Platform)

12. UCS (Universal Character Set)

13. UCS/WINS (Uniform Communication Standard)

14. UDA (Universal Data Access)

15. UDDI (Universal Description, Discovery and Integration)

16. UDF (Universal Disk Format)

17. UDMA (Ultra DMA)

18. UDP (User Datagram Protocol)

19. UEFI (Unified Extensible Firmware Interface)

20. UHF (Ultra High Frequencies)

21. UI (User Interface)

22. UICC (Universal Integrated Circuit Card)

23. UID (User ID, User Identifier)

24. ULS (User Location Service) server

25. Ultra ATA

26. Ultra SCSI

27. UltraNav

28. ULTRIX

29. UMB (Upper Memory Block)

30. UML (Unified Modeling Language)

31. UMM (UN/CEFACT Modelling Methodology)

32. UMPC (Ultra Mobile Personal Computer)

33. UMTS (Universal Mobile Telecommunications System)

34. UN/CEFACT (United Nations Centre for Trade Facilitation and Electronic Business)

35. UN/EDIFACT (United Nations rules for Electronic Data Interchange for Administration, Commerce and Transport)

36. UNC (Universal or Uniform Naming Convention)

37. unconditional jump

38. unicast

39. Unicode

40. UNII (Unlicensed National Information Infrastructure)

41. union (1)

42. union (2)

43. union (3)

44. UniPress Emacs

45. unique visitors

46. UnitedLinux

47. UNIVAC I (UNIVersal Automatic Computer I)

48. UNIX

49. UNIX socket

50. UNIX compress

51. UNIX System V Release 4.0

52. Unix-like operating system

53. UnixWare

54. unparsed entity

55. unsigned integer

56. unsigned number

57. unstructured overlay network

58. unzip

59. update

60. upgrade

61. uplink (1)

62. uplink (2)

63. upload

64. UPnP (Universal Plug and Play)

65. UPS (Uninterruptible Power Supply)

66. upstream

67. uptime

68. UPX (Ultimate Packer for eXecutable)

69. URI (Uniform Resource Identifier)

70. URL (Uniform Resource Locator)

71. URN (Uniform Resource Name)

72. usability

73. USB (Universal Serial Bus)

74. USB 2.0 (Universal Serial Bus 2.0)

75. USB drive (1)

76. USB drive (2)

77. USB drive (3)

78. USB flash drive

79. USB keyboard

80. USB Mass Storage

81. USB OTG (USB On The Go)

82. USB port

83. Usenet (User Network)

84. user

85. user account

86. user agent

87. user friendliness

88. user ID

89. user plane

90. user session

91. user sessions

92. user-level security

93. username

94. USIM (Universal Subscriber Identity Module)

95. UTF (Universal Transformation Format)

96. UTF-8 (8-bit UCS/Unicode Transformation Format)

97. utility

98. uTLD (unsponsored Top-Level Domain)

99. UTP (Unscreened Twisted Pair)

100. UTRAN (UMTS Terrestrial Radio Access Network)

101. UUcoding

102. UUCP (Unix-to-Unix Copy Protocol)

103. uuencode

104. uuencoding (Unix to Unix Encoding)

105. UUNET (UNIX to UNIX Network)

106. UW (You’re welcome)

107. UWC (Universal Wireless Consortium)

108. UXGA (Ultra Extended Graphics Array)