In 2006 I started work on Add-Art the Firefox add-on which replaces ads on websites with rotating curated art shows. The add-on is in use by 15,000-20,000 users each week and has replaced ads for over 3 years. I use it every day and it delights me everytime.
Today I am moving on from my role as the lead developer of Add-Art.
Add-Art will continue to work, but it requires a new maintainer. Perhaps you or someone you know would be interested?