Lluzhionne is a very configurable webcam program that can apply randomly selected captions, dates, and filters to images before uploading them. It comes with a default set of filters that use NetPBM and ImageMagick; others can be easily added. It can upload images using SCP. It supports Casio serial digital cameras, YUV420P and RGB24 Video4Linux devices, and grabbing images supplied by an external webcam program. It does not require X11.
It has been tested using the following cameras:
Casio QV-10a (via qvplay)
Logitec QuickCam Pro 4000 (Linux pwc driver)
Logitech QuickCam USB (qc-usb driver)
iClick Xtreme (gphoto2, identified as an Argus DC-2200)
Images supplied by Oculus, a shareware webcam app for MacOS.
Lluzhionne runs on Linux. It will probably also work to a degree on some other posixish OSes, but I haven't tested. If you're installing from the .deb package, you'll also need the 'grabframe' package (if using a v4l device).
And it has lots and lots of command line options.
The V4L support is derived from Camstream.