Tinn-R

Tinn-R has great capabilities to offer R code formatting, syntax highlighting, and broader resources like integrated IDE, easy-to-navigate GUI, multiple Unicode encodings support, and much more.

As expected, different tools target different niche programmers. Also, there are more generic and instruments that address different user needs.  Although this application's name (Tinn-R) makes it pretty difficult to believe it could be useful for other than R programming, the tool does have enough features and options to allow cross-language usage, as well as fully support other technical needs (e.g. like writing documentation).

For example, this application offers Latex support, suitable for writing extensive and complex documentation involving mathematical equations and chemical symbols.

Also, Tinn-R has useful tools for users who want to create and organize their work in a more consistent manner. The app has project management features, allows you to simultaneously work on more projects, and enables you to group, collapse, or extend same-content chunks. Also, in a separate dedicated window, you can enable and analyze differences in multiple files; as such, via color code highlighting, you check two files' differences and similarities.

There is crucial to have intuitive applications with well-built menus and easy-to-follow routines and workflows. However, there is even more important to always have a lot of samples and demo data available, for users to understand exactly how is best to use the app and for them to see the true potential of all the instruments.

Tinn-R supports a ton of well-known language syntaxes, among which C-like ones, Python, PHP, Perl, Java, R doc, R markdown, SQL, Batch MS-DOS, etc. Plus, the app has a bunch of R templates, like R script, R doc, R HTML, R markdown, or R noweb.

To conclude, the app is a solid code editor that offers code highlighting, autocompletion, and, more commonly, R-oriented templates and samples.