This user Javascript modifies rendering of Toodledo such, that notebook contents are rendered according to Markdown Syntax. As Markdown is compatible with HTML this does not limit your abilities to use the anyway supported limited HTML nativly supported by Toodledo.
The script has been tested with the Opera Browser. It should be compatible with Greasemonkey and therefore with Firefox, however this is currently untested.
For Opera simply link or copy the file toodledo.user.js into your User-Javascript directoy. You can find the location of that directory in opera:about or in the Javascript settings dialog.
For Greasemonkey add the file toodledo.user.js as described in the Greasemonkey documentation.
As part of Pagedowns code is included in the script this script this is also licensed unter the MIT License.