
Great Cow BASIC is a set of open source BASIC programming tools for Microchip PIC and Atmel AVR microcontrollers:
Great Cow BASIC has been written with three main aims – to remove the need for repetitive assembly commands, to produce efficient code, and to make it easy to take code written for one chip and run it on another. It hides many of the more confusing parts of microcontroller programming, making it suitable for beginners and those who don’t like assembly.
Thanks Sleepwalker3! Via the forum.

Awesome, just waiting for my first PIC18F’s to arrive, will definitely try this out!!
Holy cow batman!
In this blog post you show a picture of the Great Cow Graphical Basic (GCGB) which is a different download than Great Cow Basic (GCB). But the link you provide is only for the GCB About page. The link to the home page for both GCGB and GCB is here:
http://gcbasic.sourceforge.net/index.html
This thing has been around for about five years and was last updated in February of 2010.
Personally, I have not tried this thing. Plus I worry that the libraries haven’t been updated for quite awhile, so no telling what processors aren’t supported now. You might be able to update the libraries yourself, but I see no instructions on how to do this – hacking required ;-)