The &os; Project $FreeBSD$ 2015 The &os; Documentation Project &tm-attrib.freebsd; &tm-attrib.ibm; &tm-attrib.ieee; &tm-attrib.intel; &tm-attrib.sparc; &tm-attrib.general; The release notes for &os; &release.current; contain a summary of the changes made to the &os; base system on the &release.branch; development line. This document lists applicable security advisories that were issued since the last release, as well as significant changes to the &os; kernel and userland. Some brief remarks on upgrading are also presented. This document contains the release notes for &os; &release.current;. It describes recently added, changed, or deleted features of &os;. It also provides some notes on upgrading from previous versions of &os;. The &release.type; distribution to which these release notes apply represents the latest point along the &release.branch; development branch since &release.branch; was created. Information regarding pre-built, binary &release.type; distributions along this branch can be found at &release.url;. The &release.type; distribution to which these release notes apply represents a point along the &release.branch; development branch between &release.prev; and the future &release.next;. Information regarding pre-built, binary &release.type; distributions along this branch can be found at &release.url;. This distribution of &os; &release.current; is a &release.type; distribution. It can be found at &release.url; or any of its mirrors. More information on obtaining this (or other) &release.type; distributions of &os; can be found in the Obtaining &os; appendix to the &os; Handbook. All users are encouraged to consult the release errata before installing &os;. The errata document is updated with late-breaking information discovered late in the release cycle or after the release. Typically, it contains information on known bugs, security advisories, and corrections to documentation. An up-to-date copy of the errata for &os; &release.current; can be found on the &os; Web site. This section describes the most user-visible new or changed features in &os; since &release.prev;. Typical release note items document recent security advisories issued after &release.prev;, new drivers or hardware support, new commands or options, major bug fixes, or contributed software upgrades. They may also list changes to major ports/packages or release engineering practices. Clearly the release notes cannot list every single change made to &os; between releases; this document focuses primarily on security advisories, user-visible changes, and major architectural improvements.                                   Binary upgrades between RELEASE versions (and snapshots of the various security branches) are supported using the &man.freebsd-update.8; utility. The binary upgrade procedure will update unmodified userland utilities, as well as unmodified GENERIC kernel distributed as a part of an official &os; release. The &man.freebsd-update.8; utility requires that the host being upgraded have Internet connectivity. Source-based upgrades (those based on recompiling the &os; base system from source code) from previous versions are supported, according to the instructions in /usr/src/UPDATING. Upgrading &os; should only be attempted after backing up all data and configuration files.