A modern open source forum?

Question

CMS

I am looking for a forum engine in which it would be possible to add my own functionality without unnecessary crap.
Of the php-shnyh, the search did not give anything good. Almost everyone has spaghetti code, this is not acceptable. I saw attempts to do something on frameworks, but they were very raw and too primitive in terms of functionality, this is also not an option.
The idea really dawned on me that since such a misfortune has historically developed in php, then maybe it makes sense to look, say, in the direction of python engines? What about DjangoBB?
Standard requirements: live project support, good speed, security, categories, topics, posts, bb-codes. It is also desirable to have a semblance of blogs and a photo gallery.
Technical limitations: everything will spin on vps with 512mb RAM with nginx + php-fpm, there are other small php projects.

Answer 1

SMF.
It runs ubuntu.ru, for example.