Web browsers are ubiquitous: they are on every platform, every device and most people use them throughout their day for all manner of tasks. It is therefore only natural that Kolab ships with a world-class web application which exposes all the features and power of the groupware suite.

The world's most popular webmail application

The Kolab Web Application is based on Roundcube, the world's most popular open source webmail application with over half a million installations known worldwide that serve millions upon millions of users every single day. Kolab Systems is the primary sponsor of Roundcube, so the world's most popular webmail application also happens to have impecable support for Kolab.

 Comprehensive feature set

Users do not sacrifice features when using the Kolab Web Application as it supports all the features Kolab has to offer. This includes email, contacts, calendaring, notes, ToDos, resource booking, free/busy views, filter configuration, file management, folder sharing and much more.

 Universal support

The Kolab Web Application works with all modern desktop and mobile browsers and relies only on standard HTML5 support. The choice of web browser is not dictated by the use of the Kolab Web Application nor are any browser plugins or Java runtimes required.


The Kolab Web Application has been written with security in mind and has been audited for safety by security professionals. With its large global user base, many others have also examined it for weaknesses. Combined with support for ecrypted, secure HTTP commuication, the web application is a safe and secure way to access groupware data.

It also helps protect users by blocking external references to images and other resources from HTML emails until the user specifically allows them to be loaded. Combined with the spam filtering and virus protection options supported by Kolab, users are well protected from mallicious and unwanted email.

 White label ready

The look and feel of the Kolab Web Application is controled by themes. This allows organizations to easily customize and brand their installation of Kolab.

If the built-in theming is not powerful enough, due to it being open source software organizations can customize the source code itself to change any part of the user interface to their liking.


Kolab Systems stands behind the Kolab Web Application offering both enterprise support contracts as well as custom development services in addition to aiding the open source community that has grown up around the Roundcube ecosystem.