A web browser is more than an application, it is a way of thinking, it is a way of seeing the world. Epiphany's principles are simplicity and standards compliance.
Epiphany aims to utilize the simplest interface possible for a browser. Keep in mind that simple does not necessarily mean less powerful. We believe the commonly used browsers of today are too big, buggy, and bloated. Epiphany addresses simplicity with a small browser designed for the web -- not mail, newsgroups, file management, instant messenging or coffee making. The UNIX philosophy is to design small tools that do one thing, and do it well.
Epiphany also address simplicity with modularity to make a light and powerful application. If something can be implemented using external applications or components, we use it rather than wasting resources in the web browser. Integration will be achived with CORBA, Bonobo, and the ever popular command line.
Mail will be handled with your favorite e-mail application (Evolution, pine, mutt, balsa, pronto, whatever).
The introduction of non-standard features in browsers could make it difficult or impossible to use alternative products like Epiphany if developers embrace them. Alternative (standards complying) browsers could not be able to fully access web sites making use of these features. The success of non-standard features can ultimately lead to forcing one browser, on one platform to dominate the market.
Standards compliance ensures the freedom of choice. Epiphany aims to achieve this.
Epiphany is going to follow version 1.0 of the gnome user guidelines. Unless there are very serious reasons to make an exception not following it will be considered a bug. "I follow the HIG only when I like it" is not a legitimate approach. Any areas where we diverge from the HIG will communicated to the HIG team for future consideration.
Epiphany's main goal is to be integrated with the gnome desktop. We don't aim to make Epiphany usable outside Gnome. If someone will like to use it anyway, it's just a plus. For example: Making people happy that don't have control centre installed is not a good reason to have mime configuration in Epiphany itself.
Feature bloat and user interface clutter is evil :)
We will follow the new gnome policy about preferences; Havoc Pennington already explained it a lot better than we could ever do.
We target non-technical users by design. This happens to be 90% of the user population. (Technical details should not be exposed in the interface.) We target web users, we don't directly target web developers. A few geek-oriented feautures can be kept as long as they are non-obtrusive.