Folder: /3rdparty This folder contains libraries written and (un?)maintained by people or parties outside the Pcsx2 DevTeam. Libraries or code snippets written by the PCSX2 team are housed in /common instead. Cross-Compilation: Most libraries includes in /3rdparty come as either default installations in Linux distributions, or are easily obtainable. Using the PCSX2 versions included here is optional in such cases, however using the distro-provided packages is not recommended. (using PCSX2 included versions may help resolve versioning issues). Modifications: Most of these libs in /3rdparty have been tailored slightly from the original forms downloaded from the net. So if you want to upgrade to a new version you will need to do a proper diff merge. Likewise, if you modify anything in a 3rdparty library you should be sure to tag the modification with your sig or a "pcsx2" or something. Thirdly, you can use Svn Log to check for modifications, however folder renames or svn homesite changes may not have all relevant history necessary to make an accurate merge.