This script is no longer maintained, and is currently not working. A working fork is available at User:Naypta/ScriptInstaller.
The script listing page shows the scripts you installed using this tool, along with uninstall links.The script listing page, along with all .js pages, will now include install links. Just click 'em. It really couldn't be simpler.
Script Installer provides simple automatic installs and uninstalls of Wikipedia customizations (user scripts) directly from the script listing page, each with just a single click.
Each installed script listed has its own "Uninstall" link. Click it to uninstall. Again, simple.
Only scripts that were installed using ScriptInstaller will show up in this list, and only those can be uninstalled via this interface.
Technical notes
Use {{userscript}} on any page where you'd like to enable a Script Installer-compatible script link. This will provide an automated install link to anyone who uses Script Installer.
All installations are done via users' common.js pages.
Only scripts that reside on the English Wikipedia, and in User: or Wikipedia: space, can be installed using this tool.
Automatic un-installation of a particular script will only be possible if you haven't manually edited the common.js line containing that script.