Pike is an interesting programming language with syntax like C but interpreted.
Is it possible to use external C libraries in Pike? For example Apophenia: http://apophenia.info/
I could not find this in its documentation.
Thanks for your help.
Yes, it's possible and it's stated in the doc you've linked. This is covered by Writting modules in C - the CMOD step by step link.
Unfortunatelly it's not that straight-forward. You need to translate C library API into form that is understandable from Pike side. For example there are no pointers in Pike and there are no mappings or strings in C. So you need to write a CMOD that will expose the API into Pike and will do the translation. There is a number of CMODs in the Pike's source code, which you can use as an example and reference.