This validation table is only a guide to which Content Management System may produce the most valid code on installation. Out of roughly 160 CMSystems, only 30 look like they will validate 100%. Geeklog is one of those.
There are another 30-40 which look like they would only require a little tweak to validate correctly. More than half this list shows CMSystems which may have serious validation problems.
This is not designed to be a definitive answer to who validates the best code and who validates the worst. I am sure there are a lot of CMSystems that are missing from the list and i would imagine that validation would vary from time to time, as systems are constantly being tweaked and upgraded.
I have tried to include all the Open Source Systems that i could find, i have been less interested with including all the commercial CMSystems as i think they are a waste of money, especially the hosted variety. They are not likely to stand the test of time either, with so many quality open source content management systems being freely available now.
| CMS NAME | VALIDATION |
| SlashCode | VALIDATES - This Page Is Valid HTML 4.01 Strict |
| Apache Lenya | VALIDATES - This Page Is Valid HTML 4.01 Transitional |
| CoFax | VALIDATES - This Page Is Valid HTML 4.01 Transitional |
| ContentX | VALIDATES - This Page Is Valid HTML 4.01 Transitional |
| Geeklog | VALIDATES - This Page Is Valid HTML 4.01 Transitional |
| KomodoCMS | VALIDATES - This Page Is Valid HTML 4.01 Transitional |
| My Source Squiz | VALIDATES - This Page Is Valid HTML 4.01 Transitional |
| Open Rat | VALIDATES - This Page Is Valid HTML 4.01 Transitional |
| United Nuke | VALIDATES - This Page Is Valid HTML 4.01 Transitional |
| WebHareLite | VALIDATES - This Page Is Valid HTML 4.01 Transitional |
| Asset Now | VALIDATES - This Page Is Valid XHTML 1.0 Strict |
| BlogCMS | VALIDATES - This Page Is Valid XHTML 1.0 Strict |
| Campsite | VALIDATES - This Page Is Valid XHTML 1.0 Strict |
| Corinis | VALIDATES - This Page Is Valid XHTML 1.0 Strict |
| Immediacy | VALIDATES - This Page Is Valid XHTML 1.0 Strict |
| Libertas CMS | VALIDATES - This Page Is Valid XHTML 1.0 Strict |
| Nucleus CMS | VALIDATES - This Page Is Valid XHTML 1.0 Strict |
| BxCMS Bitflux | VALIDATES - This Page Is Valid XHTML 1.0 Transitional |
| CMS Form E | VALIDATES - This Page Is Valid XHTML 1.0 Transitional |
| Colony | VALIDATES - This Page Is Valid XHTML 1.0 Transitional |
| ContreXX | VALIDATES - This Page Is Valid XHTML 1.0 Transitional |
| CPG Nuke Dragonfly | VALIDATES - This Page Is Valid XHTML 1.0 Transitional |
| Live Story Board | VALIDATES - This Page Is Valid XHTML 1.0 Transitional |
| Max Dev | VALIDATES - This Page Is Valid XHTML 1.0 Transitional |
| Open PhpNuke | VALIDATES - This Page Is Valid XHTML 1.0 Transitional |
| PhpWebSite | VALIDATES - This Page Is Valid XHTML 1.0 Transitional |
| Plone | VALIDATES - This Page Is Valid XHTML 1.0 Transitional |
| Reload CMS | VALIDATES - This Page Is Valid XHTML 1.0 Transitional |
| WheatBlog | VALIDATES - This Page Is Valid XHTML 1.0 Transitional |
| Bricolage | VALIDATES - This Page Is Valid XHTML 1.1 |
| EazyCMS | 1 error - Missing an Alt else would be valid 4.01 |
| EZ systems | 1 error - missing quotes on a link else would be valid XHTML 1.0 Transitional |
| Boast Machine | 1 error - This page is not Valid XHTML 1.1 |
| GYO CMS | 1 error else would be Valid HTML 4.01 Transitional |
| Ego CMS | 1 tag error else would be valid XHTML 1.0 Transitional |
| Movable Type | 1 error else would be Valid XHTML 1.0 Transitional |
| PhpComasy | 1 error else would be Valid XHTML 1.0 Transitional |
| Elite CMS | 1 error else would be valid XHTML 1.0 Transitional |
| Ariadne | 2 errors - No DOCTYPE found! Attempting validation with HTML 4.01 Transitional |
| IM CMS | 2 errors - This page is not Valid HTML 4.0 Transitional |
| Syntax CMS | 2 errors - This page is not Valid HTML 4.01 Strict |
| FarCry Daemon | 2 errors - This page is not Valid HTML 4.01 Transitional |
| Qne CMS | 2 errors - This page is not Valid XHTML 1.0 Strict |
| Amaxus Box | 2 errors - This page is not Valid XHTML 1.0 Strict. |
| ExpressionEngine | 2 errors - This page is not Valid XHTML 1.0 Transitional |
| WordPress | 2 errors - This page is not Valid XHTML 1.1 |
| Revise CMS | 3 errors - bytes found are not valid values in the specified Character Encoding |
| Tiki-Wiki | 3 errors - This page is not Valid (no Doctype found) |
| Dynasite | 3 errors - This page is not Valid XHTML 1.0 Transitional |
| Text E | 3 errors - This page is not Valid XHTML 1.0 Transitional |
| PhpCMS | 4 errors - bytes found are not valid values in the specified Character Encoding |
| MidGard | 4 errors - This page is not Valid (no Doctype found) |
| OrbSpinner | 4 errors - This page is not Valid HTML 4.01 Transitional |
| Poseidon | 4 errors - This page is not Valid XHTML 1.0 Strict |
| PostNuke | 4 errors - This page is not Valid XHTML 1.1 |
| Saurus | 5 errors - This page is not Valid HTML 4.01 Transitional |
| Xaraya | 5 errors - This page is not Valid XHTML 1.0 Strict |
| CathDesign CMS | 6 errors - This page is not Valid HTML 4.01 Transitional |
| XHP CMS | 6 errors - This page is not Valid HTML 4.01 Transitional |
| PortalApp | 7 errors - bytes found are not valid values in the specified Character Encoding |
| Krang CMS | 7 errors - This page is not Valid HTML 4.01 Transitional |
| OpenCMS | 7 errors - This page is not Valid HTML 4.01 Transitional |
| Drupal | 7 errors - This page is not Valid XHTML 1.0 Transitional |
| 4Steps2Web | 8 errors - This page is not Valid HTML 4.01 Frameset |
| Pylucid | 8 errors - This page is not Valid XHTML 1.0 Strict |
| Lucid CMS | 8 errors - This page is not Valid XHTML 1.0 Transitional |
| RPortal CMS | 8 errors - This page is not Valid XHTML 1.0 Transitional |
| FlySpeck | 9 errors - This page is not Valid HTML 4.01 Transitional |
| WebGUI | 10 errors - This page is not Valid (no Doctype found) |
| Poociboo | 10 errors - This page is not Valid HTML 4.01 Strict |
| Manila | 10 errors - This page is not Valid HTML 4.01 Transitional |
| Xoops | 11 errors - This page is not Valid XHTML 1.0 Transitional |
| Complete Site Manager | 12 errors - No DOCTYPE found! Attempting validation with HTML 4.01 Transitional |
| Opus CMS | 12 errors - This page is not Valid (no Doctype found) |
| Cuyahoga | 13 errors - This page is not Valid HTML 4.01 Transitional |
| Magnolia | 14 errors - No DOCTYPE found! Attempting validation with XHTML 1.0 Transitional |
| Open-I CMS | 14 errors - This page is not Valid (no Doctype found) |
| Sitellite | 14 errors - This page is not Valid (no Doctype found) |
| CMS Made Simple | 14 errors - This page is not Valid HTML 4.01 Transitional |
| NQContent | 15 errors - This page is not Valid HTML 4.01 Transitional |
| Etomite | 15 errors - This page is not Valid XHTML 1.0 Strict |
| JetBox CMS | 15 errors - This page is not Valid XHTML 1.0 Transitional |
| Pigiama PGMTech | 16 errors - This page is not Valid (no Doctype found) |
| Daisy CMS | 16 errors - This page is not Valid HTML 4.01 Transitional |
| Mambo | 16 errors - This page is not Valid XHTML 1.0 Transitional |
| Guppy | 20 errors - This page is not Valid HTML 4.01 Transitional |
| NPDS | 20 errors - This page is not Valid HTML 4.01 Transitional |
| Clay Tablet CMS | 22 errors - This page is not Valid HTML 4.01 Transitional |
| PhpX | 22 errors - This page is not Valid HTML 4.01 Transitional |
| Esselbach | 23 errors - No DOCTYPE found! Attempting validation with HTML 4.01 Transitional |
| Easy Publisher | 23 errors - This page is not Valid HTML 4.0 Transitional |
| Works SiteBuilder | 23 errors - This page is not Valid HTML 4.0 Transitional |
| Joomla | 23 errors - This page is not Valid XHTML 1.0 Transitional |
| AGP CMS | 25 errors - No DOCTYPE found! Attempting validation with HTML 4.01 Transitional |
| St4nk | 27 errors - This page is not Valid (no Doctype found) |
| TopDog | 28 errors - This page is not Valid HTML 4.01 Transitional |
| Ascribe | 29 errors - No DOCTYPE found! Attempting validation with HTML 4.01 Transitional |
| Ingeniux | 29 errors - No DOCTYPE found! Attempting validation with HTML 4.01 Transitional |
| Nimbus | 30 errors - No DOCTYPE found! Attempting validation with HTML 4.01 Transitional |
| Dev-WMS | 30 errors - This page is not Valid HTML 4.0 Transitional |
| Edeptive | 30 errors - This page is not Valid XHTML 1.0 Transitional |
| Toenda | 30 errors - This page is not Valid XHTML 1.0 Transitional |
| Typo3 | 32 errors - This page is not Valid HTML 4.0 Transitional |
| DynamicWeb | 32 errors - This page is not Valid HTML 4.01 Transitional |
| Caravel | 33 errors - This page is not Valid HTML 4.01 Transitional |
| Dxm CMS | 34 errors - This page is not Valid HTML 4.01 Strict |
| Umi CMS | 35 errors - This page is not Valid HTML 4.01 Transitional |
| DotWidget | 37 errors - No DOCTYPE found! Attempting validation with HTML 4.01 Transitional |
| Integro | 40 errors - This page is not Valid HTML 4.0 Transitional |
| EasyConsole | 40 errors - This page is not Valid HTML 4.01 Transitional |
| BrowserCMS | 41 errors - No DOCTYPE found! Attempting validation with HTML 4.01 Transitional |
| Fluid CMS | 42 errors - No DOCTYPE found! Attempting validation with HTML 4.01 Transitional |
| Final Site | 46 errors - No DOCTYPE found! Attempting validation with XHTML 1.0 Transitional |
| Contenite | 46 errors - This page is not Valid XHTML 1.0 Strict |
| Ektron 300 | 49 errors - No DOCTYPE found! Attempting validation with HTML 4.01 Transitional |
| Supercharged | 51 errors - This page is not Valid HTML 4.0 Transitional |
| Polopoly | 53 errors - This page is not Valid HTML 4.01 Transitional |
| Simple Updates | 56 errors - This page is not Valid HTML 4.01 Transitional |
| Open EDMS | 60 errors - This page is not Valid HTML 4.01 Transitional |
| Contenido | 62 errors - This page is not Valid HTML 4.0 Transitional |
| Plexcor | 63 errors - This page is not Valid HTML 4.0 Transitional |
| Contelligent | 64 errors - This page is not Valid HTML 4.01 Transitional |
| OpenShare CMS | 64 errors - This page is not Valid HTML 4.01 Transitional |
| Roxen CMS | 65 errors - This page is not Valid (no Doctype found) |
| 2Flex | 70 errors - This page is not Valid HTML 4.0 Transitional |
| Site Rocket | 71 errors - This page is not Valid HTML 4.0 Transitional |
| Allinta | 75 errors - No DOCTYPE found Attempting validation with HTML 4.01 Transitional |
| Open Engine | 77 errors - This page is not Valid HTML 4.0 Transitional |
| Asbru | 78 errors - No DOCTYPE found! Attempting validation with HTML 4.01 Transitional |
| Conrad Ewerk | 81 errors - This page is not Valid XHTML 1.0 Transitional |
| Rainbow | 82 errors - This page is not Valid HTML 4.0 Strict |
| OpenEdit | 83 errors - This page is not Valid (no Doctype found) |
| Umbraco | 83 errors - This page is not Valid -//W3C//DTD XHTML 1.0 strict//EN |
| Dozing Dogs | 85 errors - This page is not Valid HTML 4.0 Transitional |
| AdxStudio | 88 Errors - This page is not Valid HTML 4.0 Transitional |
| Scoop | 95 errors - This page is not Valid (no Doctype found) |
| Content XXL | 95 errors - This page is not Valid HTML 4.01 Transitional |
| Komplete CMS | 99 errors - This page is not Valid XHTML 1.0 Transitional |
| IF CMS | 101 errors - This page is not Valid HTML 4.01 Transitional |
| Flex CMS | 104 errors - No DOCTYPE found! Attempting validation with HTML 4.01 Transitional. |
| OmniUpdate | 104 errors - This page is not Valid (no Doctype found) |
| DotNetNuke | 118 errors - This page is not Valid HTML 4.0 Transitional |
| PhpNuke | 120 errors - This page is not Valid HTML 4.01 Transitional |
| PhpWCMS | 120 errors - This page is not Valid HTML 4.01 Transitional |
| ActiveWeb | 138 errors - No DOCTYPE found! Attempting validation with HTML 4.01 Transitional |
| Php Slash | 152 errors - This page is not Valid XHTML 1.0 Transitional |
| Article Live | 154 errors - This page is not Valid XHTML 1.0 Transitional |
| Bitrix Site Manager | 160 errors - This page is not Valid HTML 4.01 Transitional |
| Community Enterprise CitySoft | 163 errors - No DOCTYPE found! Attempting validation with HTML 4.01 Transitional |
| 360 WebManager | 163 errors - This page is not Valid HTML 4.01 Transitional |
| BeYourOwn | 170 errors - This page is not Valid HTML 4.0 Transitional |
| AutoWebBuilder | 180 errors - No DOCTYPE found! Attempting validation with HTML 4.01 Transitional. |
| Shadowed Portal | 181 errors - This page is not Valid -//SW//DTD XHTML 1.1 SW//EN |
| SchoolWires Academic Portal | 181 errors - This page is not Valid HTML 4.0 Transitional |
| E-Publish | 192 errors - No DOCTYPE found! Attempting validation with HTML 4.01 Transitional |
| NX-Engine | 236 errors - This page is not Valid HTML 4.01 Transitional |
| CMS Master | 326 errors - No DOCTYPE found! Attempting validation with HTML 4.01 Transitional |
| Aiyoota | 372 errors - This page is not Valid HTML 4.01 Transitional |
| BolinOS | 387 errors - No DOCTYPE found! Attempting validation with HTML 4.01 Transitional |