Another day I needed to handle some task which included communication with a SPARQL service. Quick google search gave me a reference to the ActiveRDF project, which claims to be the thing for ruby and rails.
But the thing is that the darn thing ain't work. As the matter of fact, you won't be able even run the example from the official site. I'm not complying, used the python sparql-wrapper to accomplish the task, but this project is a good example how you should not create a Rails plugin.
And here some tips and lessons you can learn out of it.
1. Location and Versioning Control System
The project was started at the https://launchpad.net service, under the bazaar versioning control system. That's probably a progressive thinking, but still a big mistake.
All the Rails crowd currently, more or less lives on git and github. The reason is obvious, all the people in one place, it is easy to participate in the projects using quick forking and merging. No need to register and set up your account. You do it once and have them all.
I had some experience with launchpad, it's a pretty good system, and if I would start some specific project for Ubuntu, I would probably thought about launchpad, but for Rails related project, if you want the people to participate you should go to github.
The implementation as well a good example how not to write ruby code.
First of all when you creating an actual plugin or gem, global classes is the last thing which you should do. There should be the only one global name and this is the name of your project. All the rest of the things should be under the namespace.
The second is the API and what the users need to write in order to make it working in their application. With such a beautiful and powerful language as Ruby is, it is quite a shame to make people call the factory method directly. None of the actual rails part do that. There so much opportunities for all the meta-programming magic and you end up calling classes creation manually.
They should do it simultaneously to the existing things, like ActiveRecord or ActiveResource. As the matter of fact they probably should not start a standalone project in the first place and create some extension for the ActiveRecource project, they might make it to the rails codebase and that's huge. Much better than having another rails plugin.
But anyway, with a badly structured project, even if someone would like to participate and help it, that would be really hard and usually almost impossible to change anything, because there are already people who use the project as is, and people don't like to update their application code.
I don't think I should mention such basic things, that when you have year and a half old bugs in your bug-tracker, even bugs where people already posted solutions and patches and you still didn't fix the problem, that's quite suck. As well as I should not mention such simple thing like keeping your code actually working, at least with the examples you have got on the front page.
The thing is that despite the fact that you are creating an open-source project and by the license you are not responsible for anything, you actually creating a project for people. Yes I know 90% of OOS just show-off projects by rookies just out of the university. But if you want the people to take you seriously you should support your projects.
Even if you don't want to work on the project anymore and there are no one else, you probably should say something, like "sorry guys the thing didn't fly and I have better things to do". Yes that suck, but that's understandable, and responsible.
If you didn't do that, people will still come and kill their time with your buggy code and will be left pretty much alone. You should warn your customers about such things, because everyone has different situations, someone probably would be happy to spend some hours to make a dead thing walking, but someone might be on a deadline and would expect your project actually working and probably would switch to something else if was warned.
So the thing is simple. Bad location, bad implementation and bad support. This is more than enough to kill almost any project in any area. Think about it when you start your own.