Acronyms, Initialisms & Abbreviations.

http://www.ucc.ie/info/net/acronyms/acro.html Acronyms and abbreviations (English)
http://www.acronymfinder.com/ Acronyms, abbreviations and initialisms. (English)

www.cs.tut.fi/tlt/stuff/misc/babel.html Glossary of Computer Related Abbreviations and Acronyms (English)

www.epa.gov/docs/OCEPAterms Environment Related Terms, Abbreviations and Acronyms (English)
www.umr.edu/~aeg/arco/arco.html Environment Related Acronyms (English)
http://www.ucar.edu/news/acronyms/ Global Change and Environment Related Acronyms (English)
http://www-v0ims.gsfc.nasa.gov/v0ims/acronyms.html Earth Observing System Data and Information System Acronyms and Abbreviations (English)
http://www.arm.gov/docs/documents/acronyms.html Global Change and Environment Related Acronyms (English)
http://www.gcrio.org/compendium/gcacronyms.html Global Change Related Acronyms (English)
http://cdiac.esd.ornl.gov/pns/acronyms.html Global Change and Environment Related Acronyms (English)

http://www.aicpa.org/members/glossary/quickref.htm Accounting acronyms and abbreviations (English)
www.nyse.com/ Financial Glossary and Acronyms (English)
tradition.axone.ch/ Financial Terminology Database (English, French German and Italian)

www.geo.ed.ac.uk/agidexe/acronyms List of Acronyms of the Association for Geographic Information (English)
http://geonames.nrcan.gc.ca/info/prov_abr_e.php Abbreviations and symbols for the names of the canadian provinces and territories (English and French)

http://sirius-ci.cst.cnes.fr:8090/HTML/information/general/glossaire_fr.html Acronyms in the following domains: oceanography climatology, geodesy, altimetry, etc. (French)