Minecraft 1.7 did not include any major changes. They just rewrote about 50% of the source code.
Nah, not a lot.
And they're doing it EXACTLY so they can make a mod store.
Now, the only reason you cannot pay for Railcraft is because Mojang included a clause stating that you cannot sell modifications or derivative works based on Minecraft's source code. They ARE working on a mod store and API... since 2011. I believe it will be coming in the next year or so, Mojang claims January but I stopped believing them long ago.
About modifications, I started work on a way to improve mod distribution from servers to clients: AsieLauncher. It automatically generates a launcher, a list of modifications and a list of changes between modpacks. It supports delta updating, all MC versions from 1.2.3 to 1.7.2, optional mods and a lot of other things.
The plan was to add support for automatic mod updating and dependency tracking, but the problem is mod authors aren't often willing to participate, due to stubbornness or just plain assholery or laziness. That's why such projects rarely take off.
Yes, major changes—Jeb's Minecon 2013 slide showed 600,000 lines of code committed for version 1.7. [1]
Two years ago I was certain that Mojang's goal was to do a mod store, but at Minecon 2012 Jeb explicitly ruled that out in a slide titled "Making Money?" with a bullet point reading "Not via the repository or the game." [2]
Another interesting failure mode is some mod authors stop development or apparently disappear. Everything I've read implies Thermal Expansion simply stopped in 1.5.x and its still not compatible with 1.6.x or later. Of course that may be out of date or inaccurate information.
One general startup concept to think about is minecraft mods are another example of an ecosystem built on another companies playing field; much like the companies that write facebook games.
" Everything I've read implies Thermal Expansion simply stopped in 1.5.x and its still not compatible with 1.6.x or later. "
They decided to attempt a complete rewrite of the mod. It's about half-done. Yes, stupid decision, seeing as a 1.6.x port can be done in a weekend for any mod.
I wish I could make a startup, but I'm only 16... although I do have the AsieLauncher - which makes launcher creation and mod cataloguing easy, I also have contacts within the modding group with people willing to join such kind of project... But I can't take any money for it, which kind of misses the point.
An easy way to charge for Minecraft mods would be to create a Flattr-esque system for server owners: you pay a flat fee for servers, set based on server size, and the fee is proportionally distributed between mod authors, who in exchange ensure that the mod versions in the database are okay and that the configuration is in a specific format that makes it easy for the launcher to generate a server- and client-side config that just works (though "ID hell" will be gone with 1.8, when they fully make a move to referring to blocks by names and not IDs).
Yes this is an area where "the minecraft mod community" in general doesn't seem to understand the (recent) history of the FOSS movement. Not invented here syndrome on a very large scale. debian.net doesn't redirect people thru adfly to download DVD ISOs yet none of the devs are starving, and so forth.
Another area of comedy is the early 90s-like "lets make our own license" and the result of programmers trying to practice law is generally about as comical as lawyers trying to program. Yet the modding community with no sense of history has some amusing home grown licenses (sorry no links at top of my head). I compliment you personally for not falling victim to that trap (I looked at your github) but many modders have some truly weird homemade licenses.
Most of those FOSS developers are paid by (a) consulting/support fees on the FOSS they develop or (b) working for companies which use that FOSS in their products. That works fine for B2B products, but doesn't translate well to Minecraft - nobody really needs consulting/support fees on Minecraft mods, because the hosting services mostly handle that, and they sell hosting at near bottom-dollar.
The problem is that 12-year-olds are not willing to donate, and that is the major audience for most mod makers, unlike Linux distros.
Only a few get to make for the smaller crowds, and they are usually mocked throughout.
Not to mention, companies don't invest millions in Minecraft.
EDIT: MMPL (Minecraft Mod Public License) and Elo's and CovertJaguar's custom licenses are the most prominent examples. Half of the mods don't even HAVE licenses!
Minecraft 1.7 did not include any major changes. They just rewrote about 50% of the source code.
Nah, not a lot.
And they're doing it EXACTLY so they can make a mod store.
Now, the only reason you cannot pay for Railcraft is because Mojang included a clause stating that you cannot sell modifications or derivative works based on Minecraft's source code. They ARE working on a mod store and API... since 2011. I believe it will be coming in the next year or so, Mojang claims January but I stopped believing them long ago.
About modifications, I started work on a way to improve mod distribution from servers to clients: AsieLauncher. It automatically generates a launcher, a list of modifications and a list of changes between modpacks. It supports delta updating, all MC versions from 1.2.3 to 1.7.2, optional mods and a lot of other things.
The plan was to add support for automatic mod updating and dependency tracking, but the problem is mod authors aren't often willing to participate, due to stubbornness or just plain assholery or laziness. That's why such projects rarely take off.