CKEditor editing. A custom collaborative solution can be build by using the CKEditor 5 Framework components and real-time collaborative editing can be enabled by connecting to the CKEditor Cloud Services. A ready to use, drop-in component based on CKEditor 5 (Letters) offers a complete solution for real-time collaborative writing. CKEditor 4 is fully compatible with most internet browsers, including latest stable releases from Google Chrome, Firefox, Safari, Microsoft Edge, Opera and Internet Explorer 10 and 11. In mobile environments, it has close to full support in Safari (iOS6 +) and Chrome(Android) CKEditor 5 is also compatible with Google Chrome, Firefox, Safari,
Internet Explorer 9 Chrome and Internet Explorer." The release candidate was also "perfectly" compatible with far more sites than the beta, but there are still issues with some sites because their developers are not yet testing with the new browser. The RC scores 4 out of 5 ("very good") for now. On its first day of commercial availability, Internet Explorer 9 was downloaded over 2.35 million times. Blogging his March 2011 performance tests for ZDNet, Adrian Kingsley-Hughes concluded that Chrome 10, Internet Explorer 9 (32-bit) Final Release, Opera 11.01 and Firefox 4's Release candidate were "pretty evenly matched... Microsoft has worked hard on