Good & Free Editor in Mac OS with highlighting and side-by-side editing/comparison. I need it for: XML, C++ and PHP. Thanks in advance.
MacVIM (or standard Unix VIM) works well. It performs syntax highlighting for the above languages and will do side-by-side diffing.
Zoran Regvart
Check the answers given in What is a good C++ editor for Mac OS X?.
Komodo Editor will also do comparisons, and it does support all above languages and more.
TextWrangler is pretty good, you should give it a go.
来源：https://stackoverflow.com/questions/1963289/good-free-editor-in-mac-os-with-highlighting-and-side-by-side-editing-comparis