Porting Electrical Age to a different Java-based minecraft server is in principle not terribly difficult, it's reasonably well abstracted already, but there needs to be a modding api.
- Forge doesn't really have an API layer and expects devs to work directly against deobfuscated Minecraft code. Mods break every Minecraft version.
- Forge-level mods require cooperation from the client, beyond what the official client offers. Forge mods are structured so the same mod file runs on both clients and servers.
- Because of this, a server reimplementation providing Forge features must do one of three things: compromising on open-source by releasing a client mod, reimplementing the Minecraft client (hard, and hard to get people to use), or mods splitting in Forge-based client halves and new-API-based server halves (code duplication, hard to convince modders to not just use Forge).
And yes, you'd need to create a client mod. Sure, it's a compromise, but it'd still be an improvement over the current state of affairs.
Then we will be adding a way for plugins to provide new textures in resource packs.
Once that's all done, we will create a client Forge mod to allow for plugins to add new blocks rather than reuse existing ones.
We also have a pretty nice modular system for AI tasks, but it needs more stress testing with a pathfinding implementation before we start finalizing the API for it.
There's also a plain Vanilla impl as well.