This software provides an auto and manual 'Welcome to the room' script for Colloquy IRC client. Users can customize their greetings to automatically welcome new members or manually greet them as they enter the chat room.
In addition to this feature, the plug-in adds a context menu item to chat rooms. This functionality toggles whether the script will auto welcome users when they join that specific room. It is worth noting that this is a per-room setting that will be remembered across Colloquy launches.
As to prevent spamming users with welcome messages, the script won't auto-welcome the same person again unless you reset the welcome list. Thankfully, this is quite easy to do.
Usage is intuitive and well-covered by comprehensive documentation. You can toggle the script using /welcome [on|off|auto], see the names of users you have welcomed with /welcome names, or reset the name list for a specific room with /welcome reset.
The installation process is straightforward enough. Simply unzip the file and move it to ~/Library/Application Support/Colloquy/PlugIns/ (if that folder doesn't exist, create it). If it's your first plugin install, go to Colloquy and type /reload plugins. If this is an update to an existing plugin, or if the script fails to load, then simply re-launch Colloquy.
Overall, I would say the Welcome! plug-in is undoubtedly a must-have for those who manage active communities on the Colloquy IRC platform. It is easy to use, easy to install, and has comprehensive documentation, making the process painless from start to finish.