Easy PHP Thumbnail Class can be used to manipulate images and generate thumbnails. It can load images from files and generate thumbnails that can be saved to files or be generated as the current script output. The class can also perform other image manipulation functions such as adding shadows, clipping rounded corners, filters, bilineair image deformations, and more. Over 45 image manipulation functions are available.
Moonshiner is a graphical frontend for Ghostscript's PostScript-to-PDF converter. While Ghostscript (and its wrapper ps2pdf) is a very powerful instrument, it is quite challenging to use its parameters on the command line, especially if you often change the settings as to what kind of color conversion, image resampling, etc. you want Ghostscript to perform. While the author has never used Adobe's Distiller, and thus cannot really compare the two, Moonshiner (as the name suggests) is supposed to be a work-alike for the Linux world (at least GUI-wise, as the actual work is of course done by Ghostscript).
JGrit is a program that converts images from common formats (e.g. GIF, JPEG, BMP, and PNG) to source code that can be used to render the image on either the Game Boy Advance (GBA) or the Nintendo DS (NDS) system. There are already programs that do this, but none that play nicely with both Windows and Linux. It uses the grit command line tool as a backend.
retypar converts photos, drawings, etc. into text. The result can be saved as text, HTML, ANSI,or as an image (JPEG or GIF). You can influence the conversion by altering certain options (font, font size, scale factor, color etc.). This program is translated into German, English, French, Spanish, and Italian. In addition to the graphical interface, there is a batch mode that allows you to convert a number of pictures with a single command.
SILVERCODERS OCR Server is a server-based optical character recognition (OCR) and PDF conversion solution for enterprises. It is able to perform conversion of printed documents to editable and searchable formats like plain text, RTF, PDF, and HTML, providing highly accurate recognition in 189 languages. It is available as a Linux application or a stand-alone machine, with a fully documented API, very good performance, and flexible licensing rules. It has been designed specifically for the purpose of cooperation with document management systems such as SILVERCODERS DocStorage.