Kod is very simple but yet powerful code editor. It supports a number of programming languages, so the program will highlight and correct the syntax for you correctly. The program's interface was inspired by Google's Chrome browser and its tabs, so, you know, the program is also very convenient to work with.
Rasmus Andersson, a Swedish "designer/programmer/philosopher/dude" wrote this application while being bored. He wanted to write an editor for people who occasionally write codes, because those who write them all the time are probably using some professional program costing thousands of dollars. In fact, if you have some time to read the news on his personal website - he is a blast to read (Just hit his name at the bottom of the page for this program).
The program is available in 65 languages. It does not support advanced user settings right off the bat, however, the settings can be scripted, which is both interesting and very modern. On the other hand, I've tried to write some Java code in the program and while it does highlight correctly the words, it doesn't highlight curly brackets or the set of parenthesis. On the other hand, the program is still being worked on, maybe he will fix it in the near future.
In short, if you need a useful tool when writing code on your MAC OS and you are not doing it all the time, then you should download this lightweight editor. The syntax will be highlighted, and if you are working on a couple of files one at a time, then you can just switch between them easily due to a convenient interface.