You are comparing the first mass-market release of Chrome extensions with the first alpha release of Jetpack, which isn't fair. A better comparison would be the

You are comparing the first mass-market release of Chrome extensions with the first alpha release of Jetpack, which isn't fair. A better comparison would be the first dev channel release of Chrome with support for extensions. That was May 14 2009: http://news.cnet.com/chrome-extensions-draw-near-but-advanced-html-5-features-recede/ http://news.cnet.com/chrome-extensions-draw-near-but-advance... ... which is slightly before the first Jetpack alpha which was May 20 2009. In any case, the issues that both extension systems try to address have been well-known for some time. It isn't surprising that multiple people came up with similar ideas on how to fix them. ninja edit: Got timelines mixed up first time 'round