E-mail code validation is a painful job considering many e-mail clients/applications have a low-level HTML-CSS rendering support and many others have their own standards. Actually, it is worse than designing for the browser.

Fractal is a free-to-use web application for validating HTML-CSS code across 24 most-popular e-mail clients.

It simply works by pasting the code to the application and finding out if each line is validated, if not, why and in which e-mail clients.

Best of all, Fractal doesn't come with only the bad news but also suggests fixes.

P.S. Besides the desktop and web-based e-mail applications, it also checks the code for the mobile as well.

There are various new and exciting stuff with the website development like HTML5 and CSS3.

But, when it comes to designing HTML e-mails, it is still the tables and hacks for improving compatibility with different e-mail clients.

HTML E-mail Boilerplate is a project which presents a starting point for HTML e-mail design and includes solutions for the major rendering problems with the most common email clients.

The code is very well documented and the download pack includes a non-documented version).

Allowing users to invite their contacts from other networks or e-mail providers is a popular method used in social networks & web applications.

OpenInviter is an open source PHP class, written in PHP5, for importing contacts from most of the well-known e-mail providers & social networks.

Such an invite feature is great, specially when presented as optional, to gain new users/visitors to any service.

There are already ready to use integrations for:

• WordPress
• Drupal
• Joomla
• phpBB & more.

OpenInviter supports:

• Gmail
• Windows Live
• Yahoo
• Mail.com
• Facebook
• Friendster
• hi5
• Linkedin
• Twitter
• Myspace & more..