When comparing phpBB vs Flarum, the Slant community recommends Flarum for most people. In the question“What are the best web forum software packages?” Flarum is ranked 1st while phpBB is ranked 6th. The most important reason people chose Flarum is:
The extensibility allows you to install and enable only the extensions that you desire. This is beneficial to the performance. In addition it's a SPA so js and css are loaded once and retained.
Specs
Ranked in these QuestionsQuestion Ranking
Pros
Pro Open source
Source code is available on GitHub under GNU General Licence.
Pro Premium extensions
There are many great developers creating premium extensions to make it go to the next level. With those premium extensions phpBB goes far beyond any other.
Pro Extensible
Is built to be extensible and flexible.
Pro Huge extension repository
Its the forum software with the most ready to go extension repository.
Pro Very fast loading time
The extensibility allows you to install and enable only the extensions that you desire. This is beneficial to the performance. In addition it's a SPA so js and css are loaded once and retained.
Pro Open source
Released under the very permissive MIT license, the source is freely available on GitHub and the Flarum Foundation was set up to guarantee the open source nature of Flarum as well as guarantee independence.
Pro Easily expandable
Most of the features are extensions, you have free control to en- or disable and remove extensions according to your needs. That keeps Flarum thin, lean but also extremely suitable for all types of communities.
Pro Modern UI
Designed to be mobile-first, while still allowing a rich interface on desktop. Flarum is created from the ground up to be intuitive and simple to work with.
Pro Great community
The community building flarum is fantastic and very helpful!
Pro Mobile Friendly UI
Pro Lots of features
The developers do a great job adding new bells and whistles.
Pro Based on (but not built with) Laravel
Flarum is based on many components from Laravel (like Eloquent) and Symfony, thus providing a sense of familiarity to developers with experience in those frameworks.
Pro Easy installation
As long as you have access to composer, installation is a breeze. This also makes extension management install/removal very easy as the two processes are one and the same.
Pro Intuitive
Very easy to use and feels very modern, unlike most of the competition out there.
Pro Easy installation on shared hosting services
Available on softaculous (an auto-installer for web hosting control panels like cPanel).
Pro Steadily growing
In the last few months Flarum is experiencing growth like never seen before, it's definitely time to jump on board.
Pro Runs on shared hosting
Easily runs on low end shared hosting hardware as long as you have SSH access for plugins. Also available on Softaculous for auto install which makes it a 1 click job.
Cons
Con Outdated look and feel
Even the latest version of the software looks like the typical '90s forums which is now pretty outdated.
Con Slow (phpBB 3.0)
phpBB 3.0 was not optimized for slow connections.
Con Poor community communication
There is a release lifecycle, but it is not adhered to. Migrations and updates cannot be planned.
Con Need composer
Unable to test Flarum because composer is not a standard in vps.
Con Extremely complicated to install
It's extremely hard to install Flarum, especially using anything that is hosted by Amazon. Good luck with a simple install for Amazon.