Opera Software today posted Opera 7.50, a new release of its Web browser for Mac, Windows, Linux, FreeBSD and Solaris. Opera 7.50 offers a new user interface, a built-in e-mail client (with newsgroup and RSS support), a new IRC-compatible chat feature, and more. The browser is available free of charge with a sponsored advertising banner in the top-right corner of the user interface. Users can register their version to omit the advertising banner for US$39.