Here are some companies using the ErlangLanguage:
- Ericsson: Have built some large products with Erlang, including their "flagship" AXD 301 switch http://www.ericsson.com/products/hp/AXD_301_305_MultiService_Switch_Rel_7_1_TAG_MSG_MGW_pos.shtml
- BluetailAb: Have built fancy internet protocol middleware which today handles a large amount of Sweden's email at Telenordia. Since being acquired by Alteon/Nortel, Bluetail now builds internet appliances with Erlang.
- One-To-One: UK telecom who build mobile phone services with Erlang.
- CellPoint: Have built location-aware GSM services with Erlang.
- IDEALX: http://www.idealx.org/prj/idx-xmnesia/
- Sendmail, Inc.: http://www.jetcafe.org/~npc/doc/euc00-sendmail.html
- UK based Erlang Training and Consulting http://www.erlang-consulting.com/ Provide Erlang training and consulting services worldwide.
- Schlund + Partner AG: http://www.schlund.de/ uses Erlang for some backend systems.
- Process-one: http://www.process-one.net/en/ - supports ejabberd (http://ejabberd.jabber.ru/), a Jabber IM server writen in erlang.
- MochiAds: http://www.mochiads.com/ uses Erlang for their web servers (http://code.google.com/p/mochiweb/).
- Couchbase: http://www.couchbase.com/ uses erlang to write CouchDB, the open source project which powers their product, couchbase
- Basho: http://basho.com/ who writes riak
- FaceBook: The chat service runs one Erlang process for each logged in user, with assorted glue in other languages.
- DemonWare uses Erlang: http://en.wikipedia.org/wiki/Demonware