Irrlicht vs HeroEngine

Many working examples to study and learn. You can easily experiment modifying an example code to grok in full how the engine works. In the beginning of your learning curve, the example code will offer you many useful code snippets.

If you are considering writing your own engine with openGL, you might want to consider Irrlicht instead. It makes many features of any engine worth its salt easy, including events, serialization, nodes, animators, materials, logging, and animation. Bring your own sound and networking.

Especially if you compile it yourself, it can be very light in memory usage.

If you want to start game developing with C++, then Irrlicht is a good candidate since it removes most of the complications in game making in C++. It will let you obtain experience in programming and games at the same time.

This engine supports multiple formats for 3D objects and textures.

Backend completely handled by the team at Hero.

No need for Perforce, Github or any other versioning software. It is built in. Check, Compare, Merge, revert, etc.

Developers of the engine and game developers are active on the Forums and Skype for private messaging.

Able to create many types of games and scales all the way from a single area up to a full-blown MMO.

Designed for the needs of a MMO. HSL is also relatively easy to learn as scripting languages go. It was geared towards beginners, not time hardened programmers, and as such, its easier for a novice to pick it up sometimes, than a c++ programmer. That, and it was intended to be "readable" more like English.

Skype channel and forums questions answered by developers of HE and users very quickly.

Though the export pipeline may be different and currently requires 3ds Max or Maya, the format is highly optimized to reduce high quality models down to KB's.