HWSensors is a software bundle that includes drivers and applications that allow you to access information from hardware sensors available on your Mac.
FakeSMC is an open source SMC device driver/emulator developed by netkas (http://netkas.org/).
NOTE: FakeSMC & Plugins starting from v915 provide additional sensors information to HWMonitor then running on Macs. By installing FakeSMC on real Mac you should consider you know what you are doing and how to recover your system if something...
K8055 is a Mac OS X based control panel for the Velleman K8055 USB I/O card. It's a Cocoa / Obj-C application which can be used to control the K8055 from your desktop. The source will also provide a starting point for other K8055 interfacing applications.