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,
Firefox page loads. In the final category, conformance, it was determined that Firefox had "strong" conformance for JavaScript and HTML5. In conclusion, "Tom's Hardware" determined that Firefox was the best browser for Windows 7 OS, but that it only narrowly beat Google Chrome. In June 2013, "Tom's Hardware" again performance tested Firefox 22, Chrome 27, Opera 12, and Internet Explorer 10. They found that Firefox slightly edged out the other browsers in their "performance" index, which examined wait times, JavaScript execution speed, HTML5/CSS3 rendering, and hardware acceleration performance. Firefox also scored the highest on the "non-performance" index, which measured memory efficiency,