The Mozilla Project has released Camino 1.5.1, an open source Mac OS X web browser based on the Gecko 1.8 rendering engine and the Quartz GUI toolkit. It supports pretty much all the technologies that Mozilla does: HTML, XHTML, CSS, XML, XSLT, etc. 1.5 adds spell-checking, feed detection, session restore, Keychain sharing with Safari, and enhanced security for cookies, Flash, and plug-ins. Mac OS X 10.3 or later is required. Version 1.5.1 adds version 1.8.1.6 of the Mozilla Gecko rendering engine, improves ad blocking, and fixes some critical security issues. All users should upgrade.