Google Nov. 23 began allowing developers to upload their extensions to Google Chrome's extension gallery here.

This means third-party programmers will be able to write applications that "extend" the Chrome browse and later the Chrome Operating System, which was released to open source last week.

Extensions are important to help Google attract more developers behind Chrome at a time when the company is working hard to extend the browser beyond its current 3.6 percent market share. Google also recognizes that extensions enabled Mozilla to build out a healthy application development ecosystem behind the popular Firefox browser, which garners 24 percent of the market.

Google Software Engineer Lei Zheng said Google opened its gallery early to developers to give them enough time to publish their extensions ahead of the full launch. It is unclear when that will be, but this move intimates that it will be soon.

Developers can find all the information to write an extension in Google's Chrome docs and then upload a zip file of their code and an icon that helps users distinguish the extension.

Geeks can also submit text, screenshots and YouTube videos that describe the functionality of the extension, the majority of which will be reviewed via an automated process.

When a programmer uploads an extension the extensions gallery takes care of packaging and signing the app.

To help garner feedback and bug reports, Google will soon open up its extensions gallery to a small group of trusted testers ahead of the beta launch. 

Mashable highlights Chrome extensions, including a Gmail Checker, here, but ChromeExtensions.org offers a broad directory of Chrome apps.