Alex likes programming Arduino but finds that original Arduino IDE is inconvenient in some ways. And instead of looking for other open source IDE he started to build his own. He called it “MariaMole” (means “Soft Mary” in Portuguese). His IDE is fully compatible with original Arduion IDE. It imports imports settings and libraries same way. It also compiles same way as original software. The biggest difference here is a project tree. You probably noticed when project consist of many source files it becomes hard to navigate between files. If there is too many of them, you need to scroll tabs and so on.
This one gives a nice tree view and also supports multiple projects in tree. Among other features there is a multiple serial port console support, XML based project configuration and info, color themes. It still works under Windows, but hopefully it will be adapted to other platforms soon.