Google Chrome doesn’t support extensions such as Greasemonkey that let users do client-side modifications of web pages. Kazuho Oku has written a userscript called “Greasemetal” to get Greasemonkey-like functionality out of Chrome. Greasemetal executes userscripts in the following steps.

1. setup a local web server that sends userscripts to Google Chrome
2. launch Google Chrome specifying the browser to connect its AutomationProxy (an interprocess communication channel of the web browser implemented for automated UI tests) to Greasemetal
3. periodically execute JavaScript in each browser tab that inserts <script> tags to download necessary userscripts from the local web server

The following userscripts are found compatible:

• Mylingual and Japanize - a community-based web UI localization service
• oAutoPagerize - a port of AutoPagerize (the Safari version seems to be compatible with Greasemetal)

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Source:→ Matt Cutts