Here you will find a collection of BCPL tools I've gathered from the net, cleaned up and ported to the Atari ST. This involved fixing bugs, reducing stack usage and making the code compile in 16bit via Pure C (Turbo C for the Atari ST).
Source credits include:
Martin Richards - BCPL Kit
http://www.cl.cam.ac.uk/~mr10/
Robert Nordier (Translated interp to C)
http://www.nordier.com/
Serge Vakulenko (Translated cg/syn/trn to C)
https://github.com/sergev/b
I'm sure there are other...