SublimeLinter is a plugin that supports "lint" programs (known as "linters"). SublimeLinter highlights lines of code the linter deems to contain (potential) errors. It also supports highlighting special annotations (for example: TODO) so that they can be quickly located. Supports pretty much every popular language.
Ranked in these QuestionsQuestion Ranking
Pro Helps you find errors in the code
Pro Supports pretty much every language
Con Many default linters require installing Node.js
Con Tends to cause Sublime Text to run slowly
With Sublime Linter installed, dialog boxes warning that the plugin is running slowly can become a common occurrence, depending on the types of files you regularly work with.