flpsed is a WYSIWYG PostScript annotator. You can't actually edit existing documents, but you can add arbitrary text lines to existing documents. Added lines can later be re-edited with flpsed. Using pdftops, flpsed can import PDF documents and also add text to them. It is useful for filling in forms, adding notes, etc. In batch mode, it can be used to automate form filling.
The Coherent PDF Command Line Toolkit provide a robust, professional set of tools for manipulating PDF files. The operations it offers includes split and merge, linearize, encrypt, scale, rotate, crop, bookmark, stamp, watermark, annotate, attach, and much more. It's based on the camlpdf library.
dxf allows you to easily open and edit DXF (Drawing eXchange Format) files. You can export them to various image formats (BMP, PNG, GIF, etc.) or print files. Many entites are supported (lines, arcs, circles, polylines, text, trace, and solids), as well as all colors including BYLAYER. Background color can be changed from black to white. LTYPE (linetypes) are partially supported.
Garbure is a collection of dedicated distributions. Each distribution provides carefully selected tools for a specific target domain, and is completed with examples and documentation. The set of distributions forms an entity, but each distribution works also on its own. All elements are arranged in the same way for each distribution.
The Rad Inks Card Designer is an applet suited for print industry Web sites. It provides your users a simple means of conveying ideas for their business cards to you. Users can specify fonts, colors, and even add images to their cards. The final design is saved as an XML from which you can regenerate the design.
CDox is an editor for CD documents like CD covers, back sides, and booklets. It features many image processing options like sharpen, contrast, etc. One can use images and text as elements, and those elements can be flipped/rotated/resized in any way. It has easy-to-use features for previously-made images that are meant to be CD covers. It has also some features for automatic cover creation from MP3 CDs, CDs with filesystems, and CDs with video files.