Google Chrome has powerful extension support that is second only to Firefox's in the browsing world. Up until now, Chrome users were allowed to install extensions from the official Chrome Web Store, and also from third-party sources.
A third-party source in this regard is any website that is not the Chrome Web Store. This includes userscripts on Userscripts.org, or the popular Media Hint extension that enables you to bypass country restrictions on select media sites on the Internet.
One of the reasons why those extensions and scripts are not offered on the official store is that they fall short when it comes to Google Store policies.
Google announced back in November that it would require all extensions to be hosted on the company's web store. The reason Google gave was that it would improve the security for its users.
More precise, for its Windows users as it decided to enforce that rule only for Chrome Stable and Beta users. The restriction rolled out to the beta channel recently, and users may have received already the notorious "suspicious extensions disabled" warning in their web browser.
The company announced yesterday that it will enable the security feature on May 1, 2014 for Chrome stable users on Windows systems.
The consequence here is that come that day, all extensions that are installed by Chrome Stable users that are not hosted on the Chrome Web Store will be disabled automatically by the company.
And since some extensions cannot be hosted on the store due to the store policies, users won't be able to make use of them at all anymore unless they switch to the Chrome Dev or Canary channels on Windows, or use Chrome on Linux or Mac systems instead.
Check out this tutorial on how to upgrade Chrome to Dev or Canary.
The easier one of the two is the developer mode option. What you need to do here is download the Chrome extension .crx file to your system and unpack it using a program like 7-Zip. To do so, install 7-Zip first, then right-click on the extension file and select to extract it to your system.
Open chrome://extensions/ afterwards, check the "Developer mode" box on the page, and select to "load unpacked extensions". A file browser opens that you use to pick the folder of the extracted extension.
So why is Google making that change? It is true that this will block most malicious extension installations provided that those extensions won't be accepted in the Chrome Web Store.
But that is only half of it. The move gives Google full control over the extension offerings for the browser. Since it creates the policies, it controls which extensions users can install and which they won't be able to install.
While it is possible to switch to an unaffected channel or operating system, it is likely that this will impact extension developers who cannot host their extension in the official store significantly.