TinyBasic interpreter in C
In 1976 at the HomeBrew Computer Club (HBCC), there was a lot of whining about Bill Gates charging $150 for his Basic interpreter. Dennis Allison responded by printing a "Build Your Own [tiny] Basic" article, so Tom Pittman asked if anybody would buy it if it cost only $5. There seemed to be some affirmation, so Tom Pittman wrote his interpreter.
He also rewrote the original IttyBitty TinyBasic interpreter in C, translated for modern enthusiasts. An accompanying article is published in the January 2006 issue of Dr.Dobb's Journal, p.24.