SRWare Iron One of the more widely discussed variants of Chrome is SRWare's Iron, which, according to its creators, removes all the features that raised hackles with privacy advocates. These things -- the logging of input in the omnibox, for instance -- aren't just disabled by default, but disabled completely; they cannot be reactivated.
Iron's emphasis on removing features that allegedly endanger privacy comes at the cost of some functionality. For instance, Iron does not check for updates automatically, as its creators consider the presence of the updater to be another privacy issue. You have to manually install newer versions of the program, as with Chromium. You are, however, allowed to use Iron with the Google Sync feature so that bookmarks, passwords, and preferences can be synced between copies of Iron.
Some of the changes seem wholly gratuitous. If you open the extensions page in Iron and click on the "browse the gallery" link, you're taken to chrome-plug-ins.info, a compilation of Chrome plug-ins collected by SRware, rather than Google's own Chrome extensions gallery. You're allowed to manually access and browse the Chrome Web Store and install plug-ins directly from there, but it hardly seems necessary to send people somewhere else by default.
One way to get around the absence of auto-update is to use the PortableApps version of Iron, which can be updated automatically through the PortableApps launcher (although it doesn't always provide you with the most up-to-date edition of Iron). The master builds of Iron itself seem to be kept reasonably current, though. The most recent version as of this writing was version 16 (dated December 21, 2011).
Google programmer Evan Martin, who contributes to the Chromium project, has his own odd anecdote about Iron, and he points out that the privacy features in Iron are easily emulated by changing a few settings within Chrome (or Chromium) itself.