well there are still many large software written in C, e.g. nginx, lighttpd, even linux kernel.
I checked BCHS a few years back, the key piece is that it's Openbsd, if it's Linux it might have caught on, due to linux's popularity, good or bad. This could be useful for embedded device for example, but not so many embedded devices running OpenBSD, if any at all.
The C library used (https://github.com/kristapsdz/kcgi) is portable and working on linux as well. Putting this behind nginx as fastcgi seems very well doable.
there are also qdecoder or cgic or fcgi etc are totally linux ready for CGI, which by the way, all worked well. CGI is still perfect for a deeply embedded linux device.
I checked BCHS a few years back, the key piece is that it's Openbsd, if it's Linux it might have caught on, due to linux's popularity, good or bad. This could be useful for embedded device for example, but not so many embedded devices running OpenBSD, if any at all.