What are DirectAdmin, ISP Manager, cPanel written in?

Question

Network administration

Interested in what programming language DirectAdmin, ISP Manager, cPanel are written?

Answer 1

ISPmanager is written in syah, its people write from Irkutsk.

Answer 2

The control part is basically bash/perl scripts, and the panel can be written in whatever you like.

Answer 3

What is stopping you from just opening them and seeing not only what they are written on, but also how.