You're talking about late 90's-early 00's tech there (basically, LAMP architecture). It wouldn't be that hard to develop an open source, generic hierarchical forum engine that would be easier to deploy than an Apache+PHP+MySQL suite from scratch (on a dedicated Linux server that you have to completely configure all by yourself), and that would work both on a web browser and through a smartphone app.

Security would be less an issue than back then, too. We learned a lot since early PHP and early Javascript's bad practices.