Notepad++ is a free, open source Windows source code editor and Notepad replacement that does a decent job of editing JavaScript. It also supports about 50 other programming and markup languages.

The company is keeping an open mind about the editor’s future. “We want to build the best developer experience [and] see what the community is capable of doing,” said Kelly.

Today, after 10 weeks in public beta, it is making all of the editor available under the MIT open source license, ... To expand Atom, developers only need to know JavaScript and CSS.