As part of the Digital Black Belt Security Webcast Series that I'm  working on I'm building a matrix of bug tracking applications.

Do know of any that I missed ?

Which should I review first ?

http://www.axosoft.com/
http://www.countersoft.com/
http://www.techexcel.com/
http://www.nesbitt.com/
http://www.bugcollector.com/
http://www.elsitech.com/
http://www.seapine.com/
http://www.bug-track.com/
http://www.bugtracking.com/
http://www.fogcreek.com/
http://www.prtracker.com/
http://www.fesoft.com/bugcrack/
http://www.bug-defect-tracking-expert.com/
http://www.bug-tracking-guidelines.com/
http://www.granpm.com/
http://www.issuetech.com/
http://www.solidgraphics.com/
http://www.issuetrak.com/
http://www.issueview.com/
http://www.serena.com/
http://www.sparta-systems.com/
http://www.bug-tracker-software.com/
http://www.sqatester.com/bugtracking/
http://www.websina.com/bugzero/
http://www.rmtrack.com/
http://www.ebugtrack.com/
http://www.problemtracker.com/
http://www.devhound.com/
http://www.issuebridge.com/
http://www.websina.com/bugzero/
http://www.bugaware.com/
http://www.trackplus.org/
http://www.bugvisor.com/
http://www.bugcentral.com/
http://www.bugmonitor.com/
http://www.metaquest.com/
http://www.attrib.com/
http://www.eden.com/
http://www.adminitrack.com/
http://www.sourceaction.com/
http://www.fesoft.com/bugcrack/
http://www.edenbt.com/
http://www.red-gate.com/bug_tracking.htm
http://www.problemtracker.com/
http://www.bugzilla.org/
http://www.crimsonlink.com/
http://www.developersdex.com/vb/?p=1168
http://www.fastbugtrack.com/
http://www.bugsmanager.com/
http://www.softwarewithbrains.com/
http://www.prostyle.com/
http://www.elementool.com/
http://www.trackersuite.com/
http://www.soffront.com/
http://www.agileedge.com/
http://www.mantisbt.org/
http://www.extraview.com/bug_tracking.htm
http://www.frontzone.com/
http://www.lifecycletool.com
http://www.excelsoftware.com/
http://www.ultraapps.com/index.html
http://www.aceproject.com/
http://www.defectagent.com/
http://www.axiossystems.com/
http://www.soffront.com
http://www.projxpert.com/
http://www.borderwave.com/
http://www.defecttracker.com/
http://www.software-testers.com/dragonfly
http://www.tierasoft.com/
http://www.serena.com/
http://www.bugroster.com/
http://www.tuppas.com
http://www.ykap.com/
http://www.avensoft.com/
http://www.projectinsight.net/
http://www.scopetrakker.com/
http://www.defecttrackingsoftwareguide.com/
http://www.sesame.com/
http://www.work-tracking.net/
http://www.rallydev.com/
http://www.teamatic.com/
http://www.websina.com/bugzero/
http://www.bug-tracker-software.com/
http://www.bugappliance.org/
http://www.testedok.com/bip/
http://www.aldon.com/
http://www.kemma.com/
http://www.bugtracking.com/
http://www.bugaware.com/
http://www.teamshare.com/
http://www.bugbox.biz/
http://www.litwindow.com/buglister/?hk
http://www.bugopolis.com/
http://www.skyeytech.com/bugtrack/
http://www.bugvault.com/
http://www.retisoft.com/
http://www.123bugtracking.com/
http://www.websina.com/
http://www.easybugtracker.com/
http://www.developwise.com/
http://www.defectx.com/
http://www.frontzone.com/
http://www.extraview.com/
http://www.omninet.de/
http://www.officeclip.com/
http://www.atlassian.com/
http://sourceforge.net/projects/itracker
http://www.ic-soft.com/
http://www.logigear.com/
http://www.taskperfect.com/
https://www.e-spot.biz/
http://www.visible.com/
http://66.70.30.11/ecosmonet/
http://avensoft2.com/
http://www.pointinsight.com/
http://www.pcl-online.org/
http://www.ozibug.com/
http://www.trackstudio.com/
http://www.unipress.com/
http://www.tierasoftware.com
http://www.extraview.com
http://www.sesame.com/
http://www.pragmaticsw.com/
http://www.vsoftdev.com/itemx/pc/itemaction_bugtracking.asp
http://www.bughost.com/
http://www.bugimpact.com/
http://www.adminitrack.com/
http://www.logicsoftware.net/
http://www.exdesk.com/
http://www.helis.org/
http://www.zambit.com/
http://www.alceatech.com/bugtrack/
http://www.bug-tracking-software.com/
http://www.helpdesksoftwarecentral.com/
http://www.keboproject.com/
http://www.mybugreport.com/
http://www.ozibug.com/
http://www.projectlocker.com/
http://www.speedev.com/
http://www.profault.com/
http://www.desertware.com/
http://www.squishlist.com/
http://www.taskcomplete.com/
http://www.teamatic.com/
http://www.woodpecker-it.com/
http://www.serena.com/products/ecm/tracker/home.asp
http://www.novosys.de/Buggy/Buggy.html
http://www.pandawave.com/
http://www.pb-sys.com/
http://www.intasoft.net/
http://www.plus-one.com/
http://www.rti-software.com/
http://www-306.ibm.com/software/awdtools/clearcase/cclt/features/index.html
http://www.benham.net/debbugs/
http://www.newfire.com/
http://www.neuma.com/
http://samba.org/jitterbug/
http://www.gnu.org/software/gnats/
http://www.segue.com/
http://www.compuware.com/products/trackrecord.htm
http://www.mccabe.com/
http://www.stagsoftware.com/
http://www.tortuga.com.au/
http://www.agstools.com/bugtrack/
http://www.t-plan.co.uk/
http://scarab.tigris.org/
http://roundup.sourceforge.net/
http://bugsonline.sourceforge.net/
http://www.software-testers.com/
http://abuky.sunsite.dk/index.html
http://www.threerock.com/
http://www.prev.co.uk/
http://www.bug-a-boo.org/
http://www.cpts.com/
http://www.avensoft2.com
http://www.meadowdance.org/
http://www.thinmind.com/
http://www.softwareplanner.com/
http://www.bestpractical.com
http://taskey.com/
http://www.taskland.com/
http://www.webasyst.net/
http://www.veronasystems.com/
http://www.teamatic.com/
http://www.projistics.com/
http://www.smartworks.us
http://www.berthume.com/
http://www.neuma.com/
http://www.ptlogica.com/
http://www.cowsultants.com/
http://www.accurev.com/
http://www.geniesys.net/
http://www.bruender.de/
http://www.fox.se/
http://www.lynksoftware.com/
http://www.customerexpressions.com/
http://project-management-software.celoxis.com/
http://www.newatlanta.com/
http://www.pikoni.com/
http://sourceforge.net/projects/trackplus/
http://sourceforge.net/projects/hipergate/
http://sourceforge.net/projects/mantisbt/
http://sourceforge.net/projects/projectbench/
http://sourceforge.net/projects/mytracker/
http://sourceforge.net/projects/btnet/
http://sourceforge.net/projects/opinionplugin/
http://sourceforge.net/projects/bits/
http://sourceforge.net/projects/sitehelm/
http://sourceforge.net/projects/zentrack/
http://sourceforge.net/projects/bugs-bug-genie/
http://sourceforge.net/projects/itracker/
http://sourceforge.net/projects/kennwhite/
http://sourceforge.net/projects/bugsonline/
http://sourceforge.net/projects/bugfree/
http://mantisbt.sourceforge.net/
http://abuky.sunsite.dk/index.html
http://www.agstools.com/
http://www.math.duke.edu/~yu/wreq/