The 3.1.x version of the BuildCraft API is planning to be frozen really soon. It’s already semi-frozen with 3.1.1, as there is nothing but critical changes that will get in – if any. However, doors are still open for 3.2. If you need anything in the API, now is a good time to speak
Note that there’s already been requests on API for actions, this will go in 3.2. Anything else?
* EDIT * There’s a lot of answers unrelated to the API. Sorry guys, but I need to keep this one clean, so I’m removing these. The forums are open for bug reports and feature ideas.
Note for all modders relying on BuildCraft API – there has been a packaging issue between 2.2.8 and 2.2.10, where the API packaged in the releases was the 3.x API instead of the 2.x one. Since both APIs started to diverge and being incompatible, that means that including the “official” 2.2.x BuildCraft API in your mod would generate incompatibilities and crashes when installing BuildCraft along with it. I apologize for the mess here…
The BuildCraft 2.2.10 API has been re-packaged and should now include everything that is necessary. Let me know if there’s still any issue.
BTW – this API is now completely frozen. If you’re only including it in your mods, it will stay the exact same for the entire 2.2.x branch. Random API updates has been the source of a lot of frustrations, problems and incompatibilities lately, so I’m strengthening the policy. API changes are now completely forbidden from the Beta stage of a release onward.
Oh yeah – and merry Christmas to y’all!
Ok, so there’s three known problems that are reported with BC 2.2.8, just that you know:
 There can be black screens with a couple of mods integrating the API, such as Railcraft. This is really my bad, I’ve updated the API without thinking of the potential incompatiblities here. The workaround is to install 2.2.7 instead from http://www.mod-buildcraft.com/download/previous-releases/.
 The quarry doesn’t mine grass. This is a minor issue, but if it’s getting into your nerves, installing 2.2.7 works too.
 Grass doesn’t drop seeds. This is a Forge issue, I want to make some verification before releasing Forge 1.2.2 with the fix. Out soon!
* Edit * Go check out Forge 1.2.2 on http://sourceforge.net/projects/minecraftforge/files/1.2.2/
Just so that you know. SMP is still broken and I’m aware of it. Working on improving things here. If you are interested into a little bit of background, there is a bit of a technical breakthrough between the old and the new pipes implementation. In the old scheme, a pipe was using a block id. This was already a lot when just transporting items, but it became just unreasonable to keep up with that scheme with additional waterproof and conductive pipe.
Modders may be aware of the “metadata” method to extends block ids. That’s what is done for example for wool, where each colors corresponds to a different metadata. The issue is that there is only 16 values available for metadata, and that there are already used in some pipes (e.g., to determine the input of wooden pipes, or output of iron pipes).
So the new scheme relies on pipes ids that are actually item ids, maintained by the tiles. I won’t dive into more details, but in short, while this is very reliable in SSP, this bring up all kind of synchronization issues with SMP. Hence the many crashes that everybody is having.
So I’m still working on it, hoping to release a 2.2.3 soon that will fix there. Be patient though, remember that the 2.x branch is still a beta program – beta program that I’m hoping to get out soon!