A web hosting provider... They offer a pretty darn extensive list of domain registration features such as being able to facilitate domain registration in any of these top level domains: ".com .net .info .org .mobi .biz .us .asia .in .ws .at .be .cc .cn .de .fm .gs .jobs .jp .ms .nu .nz .tc .tw .uk .vg .tv .ca".
They offer several forms of shared hosting plans. The feature set is comprehensive and they have a system of easy install for a wide variety of web applications.
They offer hosting of Microsoft Outlook email services.
They offer some canned web applications you can host on a personal domain: Photo sharing, shopping cart, and podcasting.
True to the green in their name (avacado) they are "green". I wasn't able to find any explanation except a pseudo-scribble in the top of the page saying "100% of the energy used is renewable, 1% of sales donated to plant trees, investing in Hydrogen Fuel Cell Energy".