Qucs is an integrated circuit simulator which means you are able to setup a circuit with a graphical user interface (GUI) and simulate the large-signal, small-signal and noise behaviour of the circuit.
Chandler Project, a Note-to-Self Organizer designed for personal and small-group task management and calendaring. and Open Source Application Foundation.
Nathive is a libre software image editor, similar to Adobe Photoshop, Corel Photo-Paint or The GIMP, but focused on usability, logic and providing a smooth learning curve for everyone.