This is my toy interpreter. Do not expect a complete implementation at this time.
git clone https://github.com/macoun/lambda.git
cd lambda/src
make
The executable lambda will be created in the src directory.
To interpret a source file
./lambda ../examples/sandbox.scm
To land in the REPL console. Yes, you guessed it.
./lambda
It will probably be MIT licensed. At this level feel free to do what you want with the code unless you recently killed a kitten.