Stock and security related information - http://discuss.joelonsoftware.com/default.asp?design.4.460814

http://www.google.com/search?hl=en&client=opera&rls=en&q=finance++market+data+provider&btnG=Search

Reuters Data Feed Direct (RDFD) , FAST enabled data feed, allowing clients to reduce bandwidth cost. - http://rodrickbrown.com/blog/?p=122

What is ECN - http://rodrickbrown.com/blog/?p=120

Some information about mapping of difference code - http://quant.stackexchange.com/questions/7568/mapping-symbols-between-tickers-reuters-rics-and-bloomberg-tickers