One of the most important and frequently used programming tools is an integrated development environment (IDE). Many open source IDEs exist, each with a unique set of specific features. Choosing the best open source IDE will require thinking about exactly what type of programming will be done, the language to be used, and the target platform. Some IDEs will provide a wide array of tools but will come with a steep learning curve, while others could be overly simple but provide little in the way of conveniences. The best open source IDE will be one that does not interfere with workflow and provides a more convenient programming experience.
One of the benefits of choosing an open source IDE is that so many of them are available. A host of commercial IDEs have converted their licenses to open source, making previously expensive development environments available free to everyone. In addition, the open source development community has been quite invested in creating reliable IDEs for community use and has done so several times. This has left a field of very capable, very powerful open source tools.
The first two factors that can help a person decide which open source IDE is the best for his or her needs will be to determine what operating system and programming language will be used. Some IDEs are platform independent, but others are not. This could eliminate some of the choices. There are IDEs specifically geared toward a single language, and there are others that are multi-purpose and achieve their language-specific functionality through plug-ins. Finding the IDEs that support the target language also will narrow down the choices.
The features of an open source IDE are something to consider. There are simple programs that operate as little more than syntax-highlighting text editors. Alternately, there are IDEs that allow automatic code generation, preventing the need to type in standard method signatures. There are some in between the two, as well. This decision is unique to each programmer, because some will feel the larger IDEs get in the way too much, while others cannot program without those features.
The best open source IDE should have a user interface that is intuitive to the programmer. There is no reason to use an IDE if it has the important features and menus hidden someplace where the user would not normally look. Fumbling through a design that the programmer finds confusing will only waste time and cause frustration.
Finally, open source software is community supported. There have been very impressive commercial IDEs released to open source but the parent company abandoned support and the community did not pick it up. One should be certain that the chosen open source IDE still has a development community around it. This is important because programming languages change regularly and, without keeping the IDE current, it will quickly become obsolete.