Open-source software tools I have built or maintain:
dragon, a drag and drop source/target for X11. dragon file.jpg creates a window with a single entry you can drag into a file manager or web browser.
retail, a POSIX-compatible tail with regular expression support. retail -r REGEX will output the part of the file starting at the last match of REGEX, and retail -f -r REGEX1 -u REGEX2 will output the part of the file starting at the last occurrence of REGEX1, and keep outputting until REGEX2 matches.