RakNet VS RmlUi

Halo was mostly all about single player and early multiplayer/local multiplayer but their online netcode has sucked since Blood Gulch. Lots of games do networking horribly, I have been in gamedev making networking and I hate most of what people do. The ones that have a clean natting, based on enet style reliable UDP channels, RakNet style punch are better (RakNet was good until Facebook bought it). It has come a long way but also fallen back. Valve source netcode (on github) is probably the best and you can check it out here. They started with the best in Quake networking, then to Source.

Here

Raknet No longer worked on but from what I've read, it's complete and working. It has been used in many games between 2000 - 2010

Inconsistencies can be prevented by ensuring the server handles all operations and does so in a given order, then transmits the results to clients. I wrote a little about this for my game Avoyd a long while ago. Clients (including a client running the server) send an edit request via reliable ordered UDP (e.g. using Enet, Raknet, Steam Networking etc.) and the server places these in a single queue then performs the edits and sends the results back also using reliable ordered UDP.

RakNet. It's been forked but still not that active.

RakNet (UDP network library)

How about https://github.com/mikke89/RmlUi ?

Check out these: https://github.com/ocornut/imgui https://github.com/mikke89/RmlUi

See the release notes here: https://github.com/mikke89/RmlUi/releases/tag/5.0

You're right, it's a fork of libRocket. The original library hasn't seen any development in years, so in a sense RmlUi is a continuation of it too. There's been a lot of changes since then, you can see all of it in the full changelog here.

I haven't actually used either one, but there's HikoGUI (previously known as TTauri) under the Boost license and RmlUI under MIT. Not sure if they're very OS-integrated in the way you want or not.

RmlUI