cupholder

Local or remote CD tray ejection, for Linux.
cupholder can be useful:
Usage
cupholder
Or when building a project that takes a while, as a notification utility:
<build command>; cupholder
For specifying a specific device:
cupholder /dev/cdrom
All arguments are treated as device filenames.
Use -s for silent operation and set the NO_COLOR environment variable to disable colors.
Screenshot

Web server
cupholder includes a web server that can be launched with the -l or --listen flag, that lets you eject the CD remotely, just by visiting the HTTP page at port 3280 (3280 = 0x0CD0).

For ejecting the tray using curl, a command like this can then be used:
curl --silent --output /dev/null --write-out '%{http_code}\n' http://localhost:3280/
Replace localhost with the hostname or IP address of the server where cupholder -l is running.
Requirements
General info