Zendesk provides an integrated on-demand helpdesk - customer support portal solution based on the latest Web 2.0 technologies and design philosophies.
The product has an elegant, minimalist design implemented in Ruby on Rails and provides seamless integration of the back-end helpdesk SaaS to a company's online customer-facing web presence, including hosted support email-ticket integration, online forums, RSS and widgets. This is unusual, because most SaaS helpdesk solutions focus exclusively on the backend helpdesk and treat the Web as an afterthought.
The system also leverages Web 2.0 ideas on the backend, such as tag based categorization throughout instead of the usual pre-defined drop down lists, RSS feeds for every customized view and a complete REST/JSON API for virtually every entity in the system.