The ports tree, ZFS, jails, pf, and the internals of a Unix built for correctness.
Building your own package repository with Poudriere, from jail creation through a working repo other machines can actually pull packages from.
A complete walkthrough turning a FreeBSD box with two network interfaces into a working NAT router/firewall — gateway forwarding, NAT rules, and a sane default-deny ruleset.
Announced January 20, 2014, FreeBSD 10.0 replaced GCC with Clang/LLVM as the default system compiler on major architectures and debuted bhyve, the project's native hypervisor.
Released November 22, 1994 and rebased on 4.4BSD-Lite, FreeBSD 2.0 was the first release legally clear of the USL v. BSDi lawsuit's shadow — the release that secured the project's legal future.
How a disagreement over FreeBSD 5's threading and SMP architecture led Matt Dillon to fork FreeBSD 4.8 into an entirely separate project in 2003.
Created by developer Justin Gibbs on March 15, 2000 as a 501(c)(3) non-profit, the Foundation gave FreeBSD a legal entity for funding development, licensing Java binaries, and sponsoring the project's growth.
How the FreeBSD Foundation's sponsored-development model paid for real, shipped improvements to OpenSSH compatibility and the iwlwifi driver stack rather than just donating money in the abstract.
FreeBSD 15.0's actual shipped feature set: 64-bit UFS inodes by default, MIT Kerberos replacing Heimdal, a native inotify(2) implementation, and the first release supporting binary updates via pkg.
The base system's source repository moved to Git in December 2020, following the documentation repo by weeks and preceding the ports tree by several months.
ZFS arrived in FreeBSD's base system in the late 2000s, but installing directly onto a ZFS root without manual command-line setup took years longer to become a guided installer option.