Chromium is an open source spinoff of Google's Chrome browser, which means that anyone can make their own version of Chromium, as the code is freely available. Chrome and Chromium are very similar and keep up with each other in versions; Chromium is more modifiable and Chrome is more closed. It's all a matter of preference. Comodo Security Solutions, known for its suite of security software, has tossed its hat into the ring with Comodo Dragon. What separates Comodo Dragon from the other Chromium browsers--and Google's proprietary Chrome--is the added level of security.
Comodo Dragon boasts what's called "Incognito Mode," which allows you to surf with all cookies turned off, no download tracking, and no other trace of your existence. This is handy for surfing over free public WiFi, where security is an issue, or in situations where you have to share a group or guest login. Instead of having to remember to delete your cookies afterward, as with a tracks eraser, Incognito Mode prevents cookies in the first place.
Sites that happen to use Secure Socket Layer (SSL) technology for security purposes--such as entering credit card numbers--will be identified by Comodo Dragon as secure, but only if they really are. It looks for certificates and verifies them automatically. When you visit such a secure site, the conspicuous padlock appears in the browser bar. Clicking this padlock gives you information about the exact level of security and encryption that site is using. Handy when you're unsure of a site's security level, or if you feel you may have visited a spoof site.
The most recent version of Comodo Dragon is based on the newest Chromium 4, released back in August. The vanilla Chromium is up to version 5, however. You may have heard that Google is experimenting with integrating Flash with the main browser, and you won't find that reflected here.
As with other Chromium browsers (and Google Chrome), Comodo Dragon's user interface is minimalist, leaving a lot of room for the screen, and it renders pages very quickly while using little RAM and CPU. If you're already a fan of Google's browser, are OK with being a few versions behind, and want more security than the standard level, check out the free Comodo Dragon. Those who want the cutting edge, such as Flash integration and more up-to-date bug fixes, might want to stick with plain Chromium.