Some Q&A:

Why "Tendu"?

The name "BiDi" is already taken by another theme.
I googled a bit for all kinds of names, and eventually came across the name "Tendu", which is the tree from which "bidi" cigarettes are made.
It sounded clever at the time...

Why create another "starter theme"?

Tendu is the sum of my 5 years experience in HTML and CSS development for Bi-Directional websites, 2 of them using Drupal.
It was born from the lack of a light, stable, table-less and cross-browser theme that support RTL and BiDi layout "out of the box".
Tendu has a lot of the useful features that can be found in other "Starter themes" like Zen (I copied or re-wrote some of Zen's features, some good implementations there) but is much less complicated and bloated then these themes, though a bit less friendly for the non-professional user..

So, what exactly is Tendu?

Tendu, by definition, is intended to be a base for future RTL ready themes.
Version 1.x was pretty basic, and assumed the user has good knowledge in CSS.
In version 2.x I added many advanced features and made it much easier for non developers to use the theme.
Just note that to use the real power of Tendu, you should have at least basic CSS and HTML skills.

Main Features for 6.x-2.x versions:

• Table-less design, supports 1,2 or 3 columns, fixed or flexible width layouts.
• Full support for multi-language, left-to-right and right-to-left websites.
  - Said to have the best RTL support out of all the starter themes (http://drupalstaging.com/starter-themes/starter-theme-comparison.html).
• Cross-browser support for all major browsers, and reported to work on some of the older or more exotic ones (Among them IE4, IE5 and Amaya).
• Cross-browser support for 100% body height with the footer sticked to the bottom of the viewport on short pages.
• Accessibility:
  - Relative font size and well formed page structure for easy font size change and for fluent page read in screen reader.
  - Hidden links that pop on focus to the content at the top and bottom of the page for screen readers and keyboard-only navigation
  - Hidden headers to menus to comply with accessibility guidelines
• Degradable design for older and non-standard browsers to avoid the use of CSS hacks.
• Integrated "conditional-styles" module, for easy addition of IE conditional comments through the theme's .info file.
• Automatically adds the "Language Switcher" block when "locale" module is installed and more then one language is defined.
• Integrated search box, primary and secondary menus.
• Features 9 dynamic content regions for flexible design.
• Sub-theme support, inside or outside the base theme.
• CSS3 round corners for Mozilla/Webkit browsers.
• Built in support for Block Class and Block Theme modules in block.tpl
• Theme Settings form to toggle the Language Switcher and Accessibility links

Can I start using Tendu right away?

Yes. I uploaded the project to Drupal.org
Note that Tendu is still in development, though, as you can see here it is fully functional.

Click the "Project page" link at the top of the page do download the latest snapshot the theme.