- LAA Locally Administered Address
- LAN Local Area Network
- LAP Link Access Protocol / Link Access Procedure
- LAPB Link Access Procedure Balanced
- LAPD Link Access Procedure D Channel
- LAT Local Area Transport
- LATA Local Access and Transport Area
- LAVC Local Area VAX Cluster
- LCC Leaded Chip Carriers / LAN Control Center
- LCD Liquid Crystal Display
- LDT Local Descriptor Table
- LEC Local Exchange Carrier
- LED Light Emitting Diode
- LF Largest Frame
- LFN Long File Name
- LFO Low Frequency Oscillator
- LIF Low Insertion Force
- LIFO Last In First Out
- LIM Lotus Intel Microsoft
- LIM/EMS Lotus Intel Microsoft/Expanded Memory Specification
- LISP LISt Processing language
- LLAP LocalTalk Link Access Protocol
- LLC Logical Link Control
- LMMP LAN/MAN Management Protocol
- LMMS LAN/MAN Management Service
- LN:DI Lotus Notes: Document Imaging
- LOL Laughing Out Loud
- LP Line Printer
- LPM Lines Per Minute
- LR List Recursive
- LRU Least Recently Used
- LSB Least Significant Bit / Least Significant Byte
- LSI Large Scale Integration
- LSL Link Support Layer
- LU Logical Unit
- LZW Lempel-Ziv-Welch