SleePy Powered sites are site that SleePy is managing or managed. While it may be powered by some web-software like SMF the site may also be using code that SleePy himself has created and using on the site. If it is using some web-software and you can't find the mod or script on their site it is most likely a custom created script or tweak.
While creating scripts is both fun and enjoy-full they will remain private. If SleePy has posted the code for it somewhere it may be used. But requests for what was used will be denied. Please do not contact SleePy with questions about how to do something. All Functions done on SleePy Powered sites are php scripts and can be created again using your own time to find the correct or similar coding used.
Any Scripts/Tweaks that are released are not supported by SleePy, There may not be comments in the code, please do not ask for them, SleePy doesn't usually comment his code unless it is really needed. Any Scripts/Tweaks Released SleePy is not responsible for if something goes wrong or causes problems with your site. Scripts/Tweaks are provided "as is" and without any warranty.