PeShell Swapper was developped by TheTruth http://pierre-mounir.freehostia.com/#peshell
To play with it, change the timeout in the shell loder plugin or at PE run time you can also kill explorer to see the Peshell GUI.
You can look also to PEShell.ini in Program Files\PEshell.
Pecmd is a loader and script language developed by Chinese http://bbs.wuyou.net/forum.php?mod=viewthread&tid=205402
It is always active and it offers lots of possibility.
You can look at pecmd.ini in Windows\System32 or open the Help via the Pecmd systray icon.
In Chinese, it was not easy at first to understand it but now the help, the systray menu,... have been translated into English. Thanks to SIW2 and others
It is nowadays a reference in PE.