Releases in May 2006 and before

github
fluffos/fluffos on GitHub fluffos-1.35
github
lilypond/lilypond on GitHub git/start release/2.9.7
github
zopefoundation/Zope on GitHub backups/2.10@68399
gnome-gitlab
GNOME/gnome-desktop on Gnome GitLab GNOME_DESKTOP_2_14_2
sourceforge
swissfileknife on SourceForge 1-swissfileknife/1.1.1/sfk111.zip
github
ntpsec/ntpsec on GitHub NTP_4_2_1P257_RC
github
aria2/aria2 on GitHub release-0.5.0
github
octo/liboping on GitHub liboping-0.2.0
github
zopefoundation/Zope on GitHub backups/ajung-zpt-end-game@68335
gnome-gitlab
GNOME/gnome-terminal on Gnome GitLab GNOME_TERMINAL_2_14_2
github
net-snmp/net-snmp on GitHub Ext-5-3-1-pre3
github
secdev/scapy on GitHub v1.0.4.31
github
ntpsec/ntpsec on GitHub NTP_4_2_1P256_RC
github
sassoftware/conary on GitHub conary-1.0.16
github
GNOME/dia on GitHub DIA_0_95_1
github
apache/solr on GitHub releases/lucene/2.0.0
github
bestpractical/rt on GitHub rt-3.6.0rc3
Maybe you can find something interesting in this list