Colbert was my first venture into programming language design. It could be better-constructed, yet can be proven to be Turing-Complete. There is an interpreter for BF written in Colbert included as an example with the source.
Typing is loose, functions can be declared inside of functions, and there is very minimal error handling since it was developed as an academic project.
The BF programs embedded within bf.clb in the archive were mined from Wikipedia and Google searches.