Here is some basic information if you want to contribute to the development of unmarked. This is not very complete, but it should get you started.
(Note: if you use Windows, you should install R and Rtools into a directory without spaces. i.e. don't install into "Program Files". Instead, install them into directories like C:\R\R-2.15.1 and C:\Rtools)
1. Install git
2. Configure git (read the manuals and tutorials, eg http://help.github.com/win-set-up-git/ and http://git-scm.com/documentation and http://www.vogella.com/articles/Git/article.html)
3. Create a github account.
4. Go to my repo and click the "Fork" link.
5. Open the git command line window (BASH shell) and clone your new fork by typing
git clone firstname.lastname@example.org:yourAddressShownOnYourGithubPage
This will download all the source code to your computer. Let's say you issued this command from C:/
6. Move to your new local repo using:
6. Create a new branch by typing
git branch myBranch
7. Move to your new branch by typing:
git checkout myBranch
8. Start editing the code. Use your favorite text editor and try to adhere to our coding style.
9. Build and test your new version (Windows users will need to install Rtools):
R CMD build unmarked
R CMD INSTALL unmarked_x.x-x.tar.gz
R CMD check unmarked_x.x-x.tar.gz # only when you think it is ready for CRAN
10. Commit your changes and push them to your github repo using
git commit -am "I did x,y,z"
git push origin myBranch
11. Send me a pull-request and I'll merge your changes in.