INDI is an instrument-neutral distributed interface control protocol that aims to provide backend driver support and automation for a wide range of astronomical devices (telescopes, focusers, CCDs, etc.). Current supported devices include many telescopes, CCDs, filter wheels, focusers, and video cams. INDI is used in popular astronomy suites like Xephem, KStars, DCD, and Cartes Du Ciel.
pngcrush is an excellent batch-mode compression utility for PNG images. Depending on the application that created the original PNGs, it can improve the file size anywhere from a few percent to 40% or more (completely losslessly). The utility also allows specified PNG chunks (e.g. text comments) to be inserted or deleted, and it can fix incorrect gamma info written by Photoshop 5.0 as well as the erroneous iCCP chunk written by Photoshop 5.5.
Nuttx is a real-time embedded operating system (RTOS). It has a small footprint that is usable in micro-controller environments. It is fully scalable from tiny (8-bit) to moderate embedded (32-bit) systems. It also aims to be fully compliant to standards, to be fully real time, and to be totally open.
ImgView is a simple image viewer for Unix-like systems. It is free from menus and other GUI gadgets, and controlled primarily by the keyboard. It supports the following image file formats: XBM, PBM/PGM/PPM, GIF, JPEG, TIFF, PNG, and PCX. It supports RGB, Gray, and CMYK ICC profiles in JPEG, RGB and Gray ICC profiles in TIFF and PNG, and RGB ICC profiles in GIF.
S3QL is a file system that stores all its data online. It supports Amazon S3, Google Storage, and OpenStack and effectively provides you with a hard disk of dynamic, infinite capacity that can be accessed from any computer with Internet access. S3QL provides a standard, full featured Unix file system that is conceptually indistinguishable from any local file system. Additional features include compression, encryption, data de-duplication, immutable trees, and snapshotting, which make it especially suitable for online backup and archiving. The design favors simplicity and elegance over performance and feature-creep. Care has been taken to make the source code as readable and serviceable as possible. Solid error detection, error handling, and extensive automated test cases are provided.