I've received a number of questions recently about XenServer and XCP and how they are different - particularly now that XS 6.2 has been released - so thought I should try and get the answers all in one place. XenServer: As of XS 6.2, it was announced that it will be fully open sourced[1] and all features are entirely free to use (i.e. there are no paid editions) There is a new website at www.xenserver.org where the build and code is available. XCP: As XS 6.2 is fully open source, no new versions of XCP will be released[2]. You can install XS in XCP mode by selecting that option at install time, and there is an upgrade path from XCP to XS 6.2. We'd recommend all XCP users to upgrade to XenServer 6.2 Xenserver-core[3]: This is a method for building the core packages in a xenserver installation on an existing RPM-based system. Initial support for this configuration (notably running nova services in domain 0) was recently added in Havana[4]. Xcp-xapi/Kronos: This is a method of installing an old snapshot of a xenserver-core like system on Debian-based systems. Xcp-xapi is not updated with the latest changes in xapi and there will be a version of xenserver-core for Debian/Ubuntu, which will be built from the main branch and therefore continuously up to date, announced in the next few weeks. I hope this answers any questions in one place, but if there are more questions, just let me know! I have updated the page at https://wiki.openstack.org/wiki/XenServer/Install to make it a little clearer and we will of course be making similar clarifications in the install guide in the next few weeks. Thanks, Bob [1] Some source code repositories may not be available until the end of September: http://xenserver.org/overview-xenserver-open-source-virtualization/source-code.html [2] http://xenserver.org/discuss-virtualization/q-and-a/i-am-a-user-of-xcp-how-will-i-be-impacted.html [3] http://xenserver.org/discuss-virtualization/virtualization-blog/entry/making-sense-of-xenserver-vs-xenserver-core-vs-citrix-xenserver.html and http://xenserver.org/discuss-virtualization/virtualization-blog/entry/tech-preview-of-xenserver-libvirt-ceph.html - although if you intend to use xenserver-core, I'd recommend using the latest snapshot described in https://lists.xenserver.org/sympa/arc/xs-devel/2013-08/msg00027.html [4] https://blueprints.launchpad.net/nova/+spec/xenserver-core