Distrowatch report for Squid versions published:

Squid 5:

	Fedora (rawhide)
	Alpine Linux (3.13.5+)

Squid 4:

	Manjaro Linux
	Ubuntu
	Debian
	openSUSE
	Arch Linux
	Mageia
	FreeBSD
	PCLinuxOS
	CentOS
	Devuan GNU+Linux
	Gentoo Linux
	KNOPPIX
	Red Hat Enterprise Linux
	DragonFly BSD
	OpenBSD
	AlmaLinux OS
	Oracle Linux
	ALT Linux
	Clear Linux
	Calculate Linux
	Univention Corporate Server
	IPFire
	Debian Edu/Skolelinux
	Rocky Linux
	SUSE Linux Enterprise
	Zentyal Server
	NetBSD
	Karoshi
	Springdale Linux
	HardenedBSD
	Exherbo
	Vine Linux
	Untangle NG Firewall
	Network Security Toolkit
	Condres OS (not active)
	Feather Linux (not active)
	Frugalware Linux (not active)
	Lunar Linux (not active)

Squid 3.5:

	EuroLinux
	Funtoo Linux
	Scientific Linux
	SME Server
	Endian Firewall
	Asianux
	Rocks Cluster Distribution
	PLD Linux Distribution
	Devil-Linux (not active)
	Nova (not active)
	Windows Cygwin [Diladele]

Squid 3.4: (dead)

Squid 3.3: (dead)

Squid 3.2: (dead)

Squid 3.1:

	T2 SDE

Squid 3.0: (dead)

Squid 2.7:

	MidnightBSD
	Windows Native (Acme inactive)