A:
AAL Application Adaptation Layer (ATM)
ACTI Advanced Computational Technology Initiative (ER+DP+...)
ADC Analog to Digital Converter
ADFS Andrew/Distributed File System task force (DCCC)
ADPE Automatic Data Processing Equipment (Fed-speak)
ADSL Asymmetrical Digitial Subscriber Line (telco-speak)
AES Advanced Encryption Standard (NIST)
AFLA Another Four-Letter Acronym
AFS Andrew File System
AGS Alternating Gradient Synchrotron (BNL)
ALS Advanced Light Source
AMC Advanced Manufacturing Center (located at NMSU, used in PHENIX muTr work)
AMU Analog Memory Unit (usually a SCA read out by an ADC)
AN Analysis Note (PHENIX)
AOB Any Other Business
AR Activity Report (PHENIX)
ARPA Advanced Research Projects Agency
ARR Accelerator Readiness Review (RHIC)
ASAP Academic Strategic Alliances Program (DOE) And you thought you knew this one as:
As Soon As Possible
ASCI Accelerated Strategic Computing Initiative (DOE, yes, it overloads the other ASCI...)
ASE Accelerator Safety Envelope (RHIC)
ASIC Application Specific Integrated Circuit
ATF Architecture Task Force (DCCC)
ATM Asynchronous Transfer Mode
ATP Assembly and Trigger Processor (in the EVB for PHENIX)
ATR AGS To RHIC (transfer line)
AUI Associated Universities, Incorporated (once ran BNL, now BSA does)
AUP Authorized Usage Policy
AWG Application Working Group (DCCC)

B:

BA Binary Acronym
BBC Beam-Beam Counters (PHENIX)
BES Beijing Electron Synchrotron (DOE-ER-HEP)
Basic Energy Sciences (DOE-ER)
BIST Built-In Self Test
BLT Blue-Logic (aka LeCroy) Trigger (PHENIX)
BNL Brookhaven National Laboratory
BPM Beam Position Monitor (RHIC)
BSA Brookhaven Science Associated (runs BNL, successor to AUI)
BTW By The Way (Internet-ese)
C:
CAD Collider-Accelerator Department (BNL) Also appears as C-AD, C-A D, etc. 
CANPS Computer Applications in Nuclear and Plasma Physics (IEEE)
CAP Competive Access Providers (CATV-speak)
CAS Central Analysis Server (RCF)
CAT Committee on Applications and Technology (IITF)
CAVE Computer Aided Visualization Experiment (??)
CBA Colliding Beam Accelerator (progenitor to RHIC)
CBO Congressional Budget Office
CCIRDA Coordinating Committee for Information Research Development and Application (DOE?)
CC-J Computing Center-Japan (PHENIX-J version of RCF)
CDR Conceptual Design Report
CEBAF Continuous Electron Beam Accelerator Facility (DOE-ER-NP)
CERN Centre Européenne pour la Recherche Nucleaire
CERT Computer Emergency Response Team
CIAC Computer Incident Advisory Capability (DoE)
CIC Committee on Information and Communications (NSTC committee)
CIDR Classless InterDomain Routing
CIF Cells In Frames (NSF-Cornell project to provide ATM over Ethernet)
CIFS Commone Internet File System
CINC Computing and Informatics for Network Collaborations
CIR Committed Information Rate
CISE Computer and Information Sciences and Engineering (NSF, Directorate of)
CIX Commercial Internet eXchange
CLNP ConnectionLess Network Protocol (part of GOSIP)
CORBA Common Object Request Broker Architecture
CORE Council of Registrars
COTS Commercial Off The Shelf (systems)
COSE Common Open Software Environment
COSINE Cooperation (Corporation?) for OSI Networking in Europe
CPA Cathode Pre-Amp (PHENIX muTr FEE)
CRS Central Reconstruction  Server (RCF)
CSU Channel Service Unit
CRADA Cooperative Research and Development Agreements
CVS Control Version System
Career Vulnerable Scientist (PHENIX)
CVTS Compressed Video Transmission Service (FTS-specific?)
D:
DAC Digital to Analog Converter
DAQ Data AcQuisition
DASIM Deputy Assistant Secretary for Information Management (DOE of course)
DC Drift Chamber (PHENIX cental arm detector)
Detector Council (PHENIX)
DCB Data Collection Board (in PHENIX DAQ, contains 4 DCM's)
DCC Disoriented Chiral Condensate
Detector Conventional Construction (RHIC)
DCCC Distributed Computing Coordinating Committee
DCEW Distributed Computing Environment Working group (DCCC)
DCIM Data Collection Interface Module (PHENIX MVD FEE)
DCM Data Collection Module (PHENIX DAQ)
DCMW Distributed Systems Management Working group (DCCC)
DCRE Distributed Collaborative Research Environments
DD Data Distributor (PHENIX, by way of E787)
DDPM Deputy DPM
DES Data Encryption Standard (FedGov speak)
DICCE Distributed Informatics, Computing & Collaborative Environment
DICE Distributed Information Computing Environment
DISA Defense Information Systems Agency
DMS Defense Messaging System
DMA Direct Memory Access
DMU Digital Memory Unit (e.g., in PHENIX PC FEM's)
DNL Differential Non Linearity
DNR Do Not Resuscitate
DNS Domain Name System
DOE Department of Energy (I know you know that, it's included for referential integrity)
DP Defense Programs (DOE)
DPM Data Production Manager (PHENIX)
DSA Directory Service Agent (X.500)
Digital Signature Algorithm
DSP Digital Signal Processor
DST Data Summary Tape
DQS Distributed Queuing System
DSS Digital Signature Standard
DSWG Digital Signature Working Group (DOE-OSC?)
DTSUG Departmental Televideo Services Users Group (DOE-wide?)
E:
EARN Eurpoean Academic and Research Network
EC Executive Council (PHENIX)
ECL Emitter Couple Logic
EDWG ESnet DECnet Working Group
EF&I Electronics Facilities and Integration (PHENIX)
EIA Energy Information Administration (DOE)
eIC Electron-Ion Collider
EF&I Electronics Facilities and Infracstructure (PHENIX)
E/FT E-mail / File-Transfer
EHR Education and Human Resources (NSF, Directorate of)
EM Environmental Restoration and Waste Management (DOE)
EMC ElectroMagnetic Calorimeter (PHENIX)
European Muon Collaboration
EMSL Environmental Molecular Sciences Laboratory (PNL)
EMTF Electronic Mail Task Force (ESCC)
ENWG ESnet Network Working Group
EOG Experimental Operations Group (PHENIX)
EOWG Engineering Operations Working Group (sub-sub-group in FNC)
EPICS Experimental Physics Industrial Control System
EPS Emergency Purgation System (for gas in the PHENIX IR at RHIC)
Encapsulated Postscript
ER Engineering Run (PHENIX
Energy Research (DOE)
eRHIC Electrons in RHIC 
ERPUS Energy Research Power Users Symposium
ERSUG Energy Research Supercomputer User's Group
ERT Ersatz Trigger (PHENIX)
EmCal RICH trigger (PHENIX)
ERVN Energy Research Video Network
ESC Experimental Safety Committee (RHIC)
ESCC ESnet Site Coordinating Committee
ESH (&Q) Environment Safety, Health and Quality (part of BNL safety)
ESnet Energy Sciences network
ESSC ESnet Steering Committee
EVB EVent Builder (PHENIX DAQ)
EXERSUG Executive Committee ERSUG
F:
FADC Flash ADC
FAQ Frequently Asked Question (Internet cuteness)
FARNET Federation of American Research Networks
FCAL Forward Calorimeter (PHENIX)
FCC Fusion Computing Council (just when you thought you'd heard of this before..)
FCCSET Federal Coordinating Council for Science, Engineering and Technology
FCSI Fiber Channel Systems Initiative
FDR Final Design Review (PHENIX)
FEE Front End Electronics (PHENIX)
FEED Front End Electronics Defibrillator (PHENIX. Usually referred to as 'feed' or 'feed.pl')
FEM Front End Module (PHENIX)
FEPG Federal Engineering and Planning Group
FESAC Fusion Energy Sciences Advisory Council
FIPS Federal Information Processing Standard (e.g., FIPS 186 = DSS)
FIRP Federal Internetworking Requirements Panel
FIX Federal Inter-agency eXchange (connections)
FNAL Fermilab National Accelerator Laboratory
FNC Federal Networking Council
FNCAC Federal Networking Council Advisory Council
FOIA Freedom of Information Act
FPGA Field Programmable Gate Array
FTE Full Time Equivalent (as in employee)
FTP File Transfer Protocol
Field Task Proposal (DOE)
FTS Federal Telecommunications Service
FWP Field Work Proposal (BNL-speak)
FYnn Fiscal Year 19nn or 20nn
G:
GA General Atomics
GAO Government Accounting Office
GBVS Global Business Video Services (AT&T)
GCWG Group Communications Working Group (DCCC)
GDS Global Directory Service
GGLP Goldhaber Goldhaber Lee Pais (particle physics version of HBT)
GEM Gaseous Electron Multiplier
GIBN Global Interoperability for Broadband Networks (some GII program?)
GII Global Information Infrastructure
GILS Government Information Locator Services (OMB)
GIX Global Internet eXchange
GL1 Global Level 1 trigger (PHENIX)
GMH Gas Mixing House (PHENIX)
GOSIP Government Open Systems Interconnection Profile
GSA General Services Administration
gTLD generic Top Level Domains
GTM Granule Timing Module (PHENIX DAQ)
GUI Graphical User Interface
H:
HBD Hadron-Blind Detector
HBT Hanbury-Brown  (and) Twiss (astronomical version of GGLP)
HDLC High-level Data Link Control (PPP-related?)
HDSL High Bit Rate Digital Subscriber Line (telco-speak)
HEP High Energy Physics
HEPIX HEP Unix Information Exchange
HFIT High Flux Isotope Reactor
HGP Human Genome Project
HIPPI High Performance Parallel Interface
HPCC High Performance Computing and Communications
HPSS High Performance Storage System (used in DCCC and now at RCF)
HSSD High Sensitivity Smoke Detector
HTCC HEPnet Technical Coordinating Committee
HTML HyperText Markup Language (WWW)
HTTP HyperText Transfer Protocol (WWW)
I:
IAB Internet Architecture Board
IAHC International Ad Hoc Committee (re Internet Domain naming)
IANA Internet Assigned Numbers Authority (part of IETF)
IB Institutional Board (PHENIX)
IC ISODE Consortium
IEEE Institute of Electrical and Electronics Engineers
IETF Internet Engineering Task Force
IIS International Internet Services
IITA Information Infrastructure Technology and Application (NASA)
IITF Information Infrastructure Task Force (advises on NII, replaces FCCSET)
IM Information Management (DOE)
INL Integral Non Linearity
IMPACT Information Planning and Architecture Team
INTA INternational Trademark Association
IP Internet Protocol
Intersection Point (usually referred to as IR)
IPNG IPng working group (ESCC)
IPNG IP Next Generation
iPOC interim Policy Oversight Committee (re Internet Domain naming)
IR Intersection Region (usually referred to as IP)
IRC Internal Review Committee (PHENIX; follows a PPG)
IRM Information Resources Management
ISO International Standards Organization
ISOC Internet SOCiety
ISP Internet Service Provider
ISODE IISO Development Environment
ISDN Integrated Sevices Digital Network
ISR Intersecting Storage Rings
Initial State Radiation
iTLD international Top Level Domains (IETF -- I guess they've gone Hungarian in naming conventions)
ITSO Information Technology Service and Operations (under IRM)
ITS-PIT Information Technology Standards- Process Improvement Team (GOSIP?)
ITTS Integration Technology Transfer System (DOE)
ITU International Telecommunication Union
J:
JAERI Japanese Atomic Energy Research Institute
JFY Japanese Fiscal Year
JSEB Jack (Fried) SEB
K:
KIAE Kurchatov Institute of Atomic Energy
KDC Key Distribution Center (Kerberos, AFS)
KDTF Key Distribution Task Force
L:
LAN Local Area Network
LANE LAN Emulation (ATM)
LANL Los Alamos National Laboratory
LATM Local ATM
LBL Lawrence Berkeley Laboratory
LCP Link Control Protocol (PPP-related?)
LDAP Lightweight Directory Access Protocol
LDRD Lab Director's Research and Development (funds)
LL1 Local Level 1 trigger (PHENIX)
LLNL Lawrence Livermore National Laboratory
LMAP Lightweight Mail Access Protocol
LOI Letter Of Intent
LOTO Lock-Out, Tag-Out (CAD)
LSM Local Sub-system Manager (PHENIX Safety)
LUT Look-Up Table (as used in PHENIX GL1 and LL1 boards)
LVDS Low Voltage Differential Signal
LVPS Low Voltage Power Supply (nomenclature of PHENIX EF&I)
M:
MAE Metropolitan Area Ethernet (?)
MBONE Multicast Backbone
MCM Multi Chip Module (used in PHENIX MVD FEE)
MCR Main Control Room (AGS and RHIC)
MCU Multi-Channel Unit
MDC Mock Data Challenge (at RCF)
MFH Major Facility Hall (now PEH)
MICS Mathematical, Information and Computational Sciences (division of OCTR of ER of DOE, formerly OSC)
MIME Multipurpose Internet Mail Extensions
MIP Minimum Ionizing Particle
MMN Muon Magnet North (PHENIX)
MMS Muon Magnet South (PHENIX)
MOU Memorandum Of Understanding
MRE Major Research Equipment (NSF)
MSDS Material Safety Data Sheet
MTF Muon Task Force (PHENIX)
MTM Master Timing Module (part of PHENIX DAQ)
MTU Maximum Transfer Unit (telecom, network-speak)
muID Muon Identifier (PHENIX)
muTr Muon Tracker (PHENIX)
MVD Multiplicity Vertex Detector (PHENIX)
N:
NAC Network Advisory Committee (to OSC)
NANOG North American Network Operations Group
NAEP National Assessment of Educational Progress
NAP Network Access Point
NASA National Aeronatics and Space Administration
NBS NSFnet Backbone Service
NCO National Coordination Office (HPCC)
NCP Network Control Protocol (PPP-related)
NetCDF Network Common Data Format (www.unidata.ucar.edu/packages/netcdf/)
NEPA National Enviromental Protection Act
NERSC National Energy Research Supercomputer Center
NFS Network File System
NGI Next Generation Internet
NIC Network Interface Card
NIE Networking Infrastructure for Education (NSF)
NIFS National Institute for Fusion Studies (Japan)
NIH Not Invented Here
NII National Information Infrastructure
NIST National Institute for Standards and Technology
NMSU New Mexico State University
NMTF Network Monitoring Task Force (ESCC)
NOAA National Oceanic and Atmospheric Administration
NP Nuclear Physics
NPRM Notice of Proposed Rule Making (?), (.gov speak)
NRC National Research Council
NREL National Renewable Energy Laboratory
NREN National Research and Education Network
NSA National Security Agency
NSAC Nuclear Science Advisory Council
NSB National Science Board
NSF National Science Foundation
NSI Network Solutions, Inc
NSIO NASA Science Internet Office
NSP Network Service Provider
NSTC National Science and Technology Council
NTIA National Telecommunications and Information Administration (Commerce)
NTIS National Technical Information Service
NTC New Trigger Counter (PHENIX)
NTP Network Time Protocol
O:
OCTR Office of Computational and Technology Research (DOE-ER)
ODH Oxygen Deficit Hazard
OFES Office Fusion Energy Sciences (DOE)
OHER Office of Health and Environmental Research (DOE-ER)
OIT Office of Industrial Technologies (DOE)
OLE Object Linking and Embedding (?, Microsoft?)
OMB Office of Management and Budget
ONCS ONline Control System (PHENIX)
OODB Object Oriented Data Base
OPC OLE for Process Control
ORBIT Optical Ring using Buffer Insertion Technology (IBM)
ORNL Oak Ridge National Laboratory
ORR Operational Readiness Review (RHIC)
OSC Office of Scientific Computing (within DOE-ER)
OSETI Office of Science, Education & Technical Information (DOE)
OSF Open Software Foundation
OSI Open Systems Interconnection
OTA Office of Technology Assessment (Congress)
P:
PAB Policy Advisory Body (directs POC)
PAC Program Advisory Committee
PASS Personnel Access Safety System (RHIC)
PbGl Lead Glass (e.g., as in PHENIX EMC)
PbSc Lead Scintillator (e.g. as in PHENIX EMC)
PC Personal Computer (of course)
Pad Chamber (PHENIX central arm detector)
PCAS Portable Channel Access Servers (used on PC's to talk to wider EPICS network??)
PCAST Presidential Committee (Council?) of Advisors on Science and Technology
pCDR Pre-CDR
PCI Peripheral Component Interconnect (PC industry)
PEH PHENIX Experimental Hall (formally MFH)
PEM Privacy Enhanced Mail
PFTP Parallel FTP (as used at RCF)
PHENIX Pioneering High Energy Nuclear Interaction eXperiment
PHENIX-J PHENIX in Japan
PIC Person In Charge (PHENIX)
PISA PHENIX Integrated Simulation Package
PGP Pretty Good Privacy (public domain utility)
PKCS Public-Key Cryptography Standards
PKI Public Key Infrastructure
PLC Programmable Logic Controller
PLL Phase-Locked Loop
PM Project Management (PHENIX)
Partition Module (in a DCM crate)
PMC PCI  Mezzanine Card
PMT Photo Multiplier Tube
PNL Pacific Northwest Laboratory
POC Policy Oversight Committee (see iPOC)
POP Point Of Presence
POTS Plain Old Telephone System
PPC Power PC
PPG Programmable Pulse Generator (PHENIX DAQ)
Paper Preparation Group (PHENIX)
PPP Point-to-Point Protocol
PPPL Princeton Plasma Physics Laboratory
PRDF PHENIX Raw Data Format
PSB PHENIX Speakers' Bureau
PSTN Public Switched Telephone Network
PWG Physics Working Group (PHENIX)
Policy Working Group (sub-comm of FNC)
Q:
QA Quality Assurance
QGP Quark Gluon Plasma
QLI Quench Link Interlock (RHIC)
QVC Charge to Voltage Converter (in PHENIX TOF FEE, ask Chi about Q for Charge)
R:
RA Routing Arbiter (as in new NSFnet model)
RARE Reseaux Associes pour la Recherche Europeenne
RBIB Reduced Bit Input Board (PHENIX)
RBOC Regional Bell Operating Companies
RBUP RHIC Beam Use Proposal
RC Run Coordinator (PHENIX)
Run Control (alas, also PHENIX)
RCF RHIC Computing Facility
RCMS Rack Control and Monitoring System (PHENIX)
RCWG Remote Conferencing Working Group (ESCC)
RF Radio Frequency (generic)
Rejection Factor (as in PHENIX trigger)
RFC Request For Comment (Internet)
RFI Request For Information
RHIC Relativistic Heavy Ion Collider (BNL)
RICH Ring Imaging CHerenkov counter
RNP Regional Network Provider
ROC Read Out Controller (PHENIX PC)
RP Reaction Plane
RSN Real Soon Now
RVWG Reliability and Vulnerability Working Group (IITF)
S:
SA1 Shift Assistant 1 (PHENIX)
SA2 Shift Assistant 2 (PHENIX)
SAC Supercomputer Access Committee (DOE-ER)
SAD Safety Assessment Document (RHIC)
SBIR Small Business Innovative Research
SBMS Standards Based Management System  (part of BNL Safety)
SCA Switched Capacitor Array
SCI Scalable Coherent Interface
SCIE Scientific Computing Information Exchange council
SEB Sub Event Buffer (PHENIX DAQ)
SE&I Systems Engineering and Integration (PHENIX)
SIF Security Issues Forum (under IITF)
SDH Synchronous Digital Hierarchy (international form of SONET)
SDIS Switched Digital Integrated Service
SHEBA Surface Heat Budget of the Arctic (NSF)
SI-PMO Security Infrastructure Program Management Office (see www.nsa.gov)
SL Shift Leader (PHENIX)
SLAC Stanford Linear Accelerator
SMC Sprint Meeting Channel (video?)
SMCS Safety Monitoring and Control System (RHIC)
SMD Shower Max Detector (integrated with PHENIX ZDC)
SMDS Switched Multimegabit Data Service
SMTP Simple Mail Transfer Protocol
SNA Systems Network Architecture (IBM)
SNL Sandia National Laboratories
SONET Synchronous Optical Network
SOW Statement Of Work
SPE Synchronous Payload Envelope
SPP Special Parallel Processing (NERSC program)
SSP Science Simulation Plan (DOE)
STAR Ask Glenn
STM-1 Synchronous Transport Module-Level 1 (= STM-3c, really)
STS-n Synchronous Transmission Speed (??) = n * 51.84 Gb/s (aka OC-n)
SVC Switched Virtual Circuit (ATM)
SWG Security Working Group (sub-comm of FNC)
T:
TAC Time to Amplitude Converter
Technical Advisory Committee
TCIM Timing and Control Interface Module (PHENIX MVD FEE)
TCP Transmission Control Protocol
TEC Time Expansion Chamber (PHENIX central arm detector)
Total Estimated Cost
TERENA Trans-European Research and Education Networking Association (=RARE+EARN as of 01-Nov-1994)
TIIA Telecommunications and Information Assistance Program (NTIA-Commerce)
TLD Top Level Domains (IETF)
TLA Three Letter Acronym
TLD Top Level Domains (IETF)
TOF Time Of Flight
TPC Time Projection Chamber
TPWG Technology Policy Working Group (of IITF)
TQM Total Quality Management
TTL Transistor-Transistor Logic
TUBA TCP and UDP with Bigger Addresses
TVC Time to Voltage Converter (e.g., in PHENIX TOF FEE)
U:
UCAID University Corporation for Advanced Internet Development (Internet2)
UDP User Datagram Protocol
URL Uniform Resource Locator (WWW)
UVC Universal Voltronics Corporation 
V:
vBNS very high speed Backbone Network Service
VCC Video Conferencing Center (ESnet)
or "" Control "" ?
VCS Video Conferencing Service (ESnet)
VRDC Virtually Real Data Challenge (PHENIX)
VTC Video TeleConference
W:
WAIS Wide Area Information Servers
West Antartic Ice Sheet (NSF)
WBS Work Breakdown Structure
WET ICE Workshop on Enabling Technologies (on) Infrastructure for Collaborative Enterprises
WIPO World Intellectual Property Organization
WWW World Wide Web
X:
Y:
YADA Yet Another Documentation Area (coined by Charlie Maguire)
YAFLA Yet Another Five-Letter Acronym
Z:
ZDC Zero-Degree Calorimeter (RHIC)