Note also that this list does not include distributions of larger collections of software of which Subversion is but one piece. Several vendors offer such things, but we concern ourselves primarily with Subversion itself. As such, the listing here is limited to those packages which may be reasonably considered binary distributions of Apache Subversion alone. If you are looking for more widely scoped, Subversion-related value-add offerings, we trust that your favourite search engine can facilitate that for you.
AIX

AIX Open Source Packages (maintained by Michael Perzl)
Centos Linux

Debian Linux

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WANdisco (supported and certified by WANdisco; requires registration)
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Debian Project (maintained by Debian Project)
$ apt-get install subversion
Fedora Linux

Fedora Project (maintained by Joe Orton)
$ yum install subversion
FreeBSD

$ cd /usr/ports/devel/subversion $ make install
HP-UX

HP Porting Centre (maintained by Connect Internet Solutions Ltd.)
Net BSD

pkgsrc (maintained by Eric Gillespie)
$ cd /usr/pkgsrc/devel/subversion $ make install clean
Open BSD

OpenBSD Project (client and server; svnserve is part of the subversion package, mod_dav_svn is in the separate ap2-subversion package)
$ pkg_add subversion $ pkg_add ap2-subversion
Mac OSX

WANdisco (client and server; supported and certified by WANdisco)
Fink (requires Fink; maintained by Christian Schaffner)
openCollabNet (universal; maintained by Jeremy Whitlock; requires registration)
RedHat Linux

WANdisco (supported and certified by WANdisco; requires registration)
CollabNet (client only; supported and certified by CollabNet; requires registration)
SummerSoft (Red Hat 8,9+; maintained by David Summers)
Solaris

Suse Linux

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WANdisco (supported and certified by WANdisco; requires registration)
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CollabNet (client only; supported and certified by CollabNet; requires registration)
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OpenSUSE project (OpenSUSE and SLES; client and server; svnserve is part of the subversion package, mod_dav_svn is in the separate subversion-server package)
$ zypper install subversion $ zypper install subversion-server
Ubuntu Linux

WANdisco (supported and certified by WANdisco; requires registration)
Ubuntu Packages (maintained by Ubuntu Project)
$ apt-get install subversion
Windows

WANdisco (32- and 64-bit client and server; supported and certified by WANdisco)
CollabNet (client only; supported and certified by CollabNet; requires registration)
SlikSVN (32- and 64-bit client MSI; maintained by Bert Huijben, SharpSvn project)
VisualSVN (client and server; supported and maintained by VisualSVN)
Win32Svn (32-bit client, server and bindings, MSI and ZIPs; maintained by David Darj)