"SourceMod is server modification for any game that runs on the Half-Life 2 engine. It is a powerful, highly optimized platform for scripting plugins and handling server administration. The default package comes with a base set of plugins, but there are over 2,500 plugins in the community." - Sourcemod About Page
As seen above, Sourcemod comes with a set of basic plugins, and this page acts as the page for those plugins due to the fact it would be unnecessary to put them all in separate pages. ( Plugins page.)
This acts as a placeholder until people add the information about those plugins to this page.