From NextUp.com:

Text-to-Speech software leader NextUp.com (www.NextUp.com) has released version 2.068 of its popular TextAloud software. This upgrade includes a new Firefox Browser Plugin which adds a TextAloud toolbar to the popular web browser, allowing users to listen to web pages read aloud on their computer. Also, users can easily convert text from web news and web based emails to audio files for portable listening. This addition compliments the Outlook and Internet Explorer toolbars also available with TextAloud to make audio browsing of the internet even easier.

TextAloud uses the Microsoft Speech API (SAPI) to interoperate with different TTS (Text-to-Speech) engines. NextUp.com is a popular reseller of TextAloud as well as different TTS engines.