KompoZer's WYSIWYG editing capabilities are one of the main attractions of the software. In addition, KompoZer allows direct code editing as well as a split code-graphic view.
The current pre-release is KompoZer 0.8 beta 3, released February 2010, using Gecko 1.8.1. The stable version was 0.7.10, released in August 2007.
KompoZer complies with the W3C's web standards. By default, pages are created in accordance to HTML 4.01 Strict and use Cascading Style Sheets (CSS) for styling, but the user can change the settings and choose between:
- Strict and transitional DTD's
- HTML 4.01 and XHTML 1.0
- CSS styling or the old <font> based styling.
- The application can call on the W3C HTML validator, which uploads pages to the W3C Markup Validation Service and checks for compliance.