FreeImage is a library project for developers who would like to support popular graphics image formats (PNG, JPEG, TIFF, BMP and others). Some highlights are: extremely simple in use, not limited to the local PC (unique FreeImageIO) and Plugin driven!
All-in-one program for creating 2D scrolling games. Compile your games into stand-alone .NET executables or customizable C# source code. The IDE and framework are build on OpenTK, which wraps OpenGL, so generated games can be cross-platform.
CDG Editor is a tool that allows the user to edit the contents of a CDG file (typically extracted from a karaoke disc as mp3+g). v1.3 now supports all CD+G command types. Please note that this is not a Karaoke creation or editing tools (see some of the comments below) - it is for fixing the CDG files that you have where the text is corrupt due to a poor rip from the original CD+G disk. You have to edit individual CD+G tile commands. This tool could be used to change the lyrics of a song for example, but it would be very difficult - that's not its purpose. Thanks for the feedback though. I've installed it on several Windows 7 64bit PCs but haven't tested the installer or the app on Windows 8 yet. Let me know via the support pages if you have problems and I'll see what I can do to help.
A powerful C++ class library for image manipulation
ImageStone is a powerful C++ class library for image manipulation. Its features include load, save, display, transformation, and nearly 100 special image effects. It can be used cross platform (includes Windows, Linux, Mac), and especially under windows it can be used as a DIB wrapper class.
ConnectCode Software Box Shot Maker creates realistic images of 3D boxes for your softwares using three image files. You can adjust the box orientation, box and camera position. Despite being opensource, the tool delivers professional results.
Extend.NET is a software allowing users to correct every errors of a picture. Specially for photographers. It contains filters form very basics of image manipulation to very complex ones.
PIAE is small utility which allows exporting all files from Picasa album with preserved desired pictures order - PROJECT MOVED TO http://code.google.com/p/piae/
Picture editor for Pocket PC, Windows CE and desktop Windows, suitable for icon editing and for canvas drawing. Allows zooming, selection copy-move-resize, pencil, brush, airbrush, bloor brush, flood fill, lines, ellipses, rectangles.
.Net application for image histogram equalization and specification. Program is able to enhance contrast adjustment. Usable for images with dynamic range flaws. You can analyze images with RGB or HSV histogram too.