If you are looking for a certain software, for alternatives or you’re simple curious, the Arch Wiki has a very nice and big list containing tons of software available for Arch Linux or any other GNU/Linux distros (although it might be harder to install):

The list is ordered in categories and sub-categories, containing many links to their specific Wiki entries (if any) and to the official websites or GitHub and Wikipedia pages.
Plus it’s smartly split between console and graphical software and there are many other links to Wikipedia comparisons or to Arch Wiki articles.

Enjoy! [:)