Eclipse IDE Download for your Mac OS PC for completely free. It is an extensible tool for Java IDE. Here from Fileion, you can easily download and install it on Mac OS.
Eclipse is an integrated development environment. It is one of the most popular tool to develop applications using the help of Java, C/C++, Python, PERL, Ruby etc. programming languages.
It is totally free and open-source application specially developed for JAVA. It has an extensible plug-in system that will allow you to customize the environment. As is really user-friendly a developer will love to use it.
Eclipse IDE is really an wonderful software for developing applications. If you are a developer then you must try it and compare it with other IDE.