FLOSS Web Application with the longest predictable security support period

Note: this one, I am not sure. Let's do some research to see if this true. (and if not, let's learn from that other project 😊

Some dude wrote:

Need a clever quote here as to why LTS is really important

Tiki is the Free/Libre/Open Source Software Web Application with the longest support period

FLOSS -> http://en.wikipedia.org/wiki/Free_and_open_source_software
Web Application -> http://en.wikipedia.org/wiki/Web_application (This includes Wiki, CMS, Groupwares or any application comparable to Tiki)
longest predictable support period: Tiki offers a choice of rapid release or Long Term Support (LTS). Tiki 12 LTS will be supported for 5 years. See: Version Lifecycle

Others FOSS Web apps which offer LTS

Typo3 3 years
MediaWiki 3 years
Joomla 2 years and 3 months
OpenERP 4.5 years
Nuxeo 3 years
With WordPress, you need to always stay in a rapid release cycle even when your site has all the features you need because WordPress doesn't offer an LTS verson and this is unlikely to change because the project leader is "philosophically opposed" to Long Term Support (LTS) versions.

Drupal

At any given time, there are two major release series of Drupal which are supported. There is no fixed release schedule o it's not predictable. This being said, historically, there is a release every 3 years, and it take about 18 months before extensions are ready for an average site, so you get an effective support for 4.5 years.