CH: The biggest thing E17 brings to the table is universal compositing. This means you can use a composited desktop without any GPU acceleration at all, and use it nicely. We don't rely on software fallback implementations of OpenGL. We literally have a specific software engine that is so fast that some developers spent weeks using it accidentally, not realising they had software compositing on their setup. E17 will fall back to software compositing automatically if OpenGL acceleration doesn't work. It is that good. It even works very nicely on an old Pentium-M @ 600Mhz with zero accelerated rendering support. I've seen it working on ARM embedded systems at high resolution wondering, "hmm the OpenGL drivers need a little work", when actually later I found out they were not even there yet and it was falling back to software. This same compositing engine is actually used for everything in E17's UI and in EFL. That engine is called Evas and it's available for use by anyone as it is just a library.
The H: What's the Samsung connection?
CH: Some Enlightenment hackers work for Samsung, helping them use E and EFL for their products and projects such as Tizen. Samsung uses E and EFL because it fits the bill for creating lean devices such as phones, TV's, etc. By being lean and flexible, Enlightenment found itself being used by Samsung because nothing else came close to the features, footprint and performance.
The H: Is E17 a proving ground for the EFL libraries?
CH: Yes. It used to be the only one, but these days Tizen uses EFL for all native UI applications and it gets quite some beating up there.
The H: What was your reasoning behind breaking out the window manager functions into the EFL libraries? What are they being used for?
CH: They were broken out to share them, not to hoard them. In fact they never were part of E17. They were written as stand-alone libraries from day one in order to make the work that we have done available to everyone, so they can benefit from it too. The libraries are openly licensed (a combination of LGPL and BSD), thus allowing you to build anything you like on top of them without hindrance. As a result of breaking them out we have eventually even built a whole GUI widget toolkit (in fact several along the years), and they are used by various applications as well.
The H: Do you eat your own dog food?
CH: Indeed we all do. It's a core ethos. We all use E17 day to day. We all use EFL day to day, too. When one of us adds a bug, developers see it really quickly and fix it because we suffer from that bug ourselves long before it ever makes it into a release. There is now a long tradition of "spanking" developers who do this on the mailing lists and IRC channels. Because of the instant visibility of issues and quick fixes, issues tend to be avoided due to the publicity, and, if they do happen, they get fixed rapidly. This tends to make our "trunk" development tree one of the more stable source repositories around even if you look at it at any point, it most likely is working quite well for a large set of people, so if you have issues you've found a rare corner-case, or the problem is on your end.
The H: What have you been doing as a project recently?
CH: We have been improving our base libraries. We have been adding features, optimizations, bug fixes. We have also been adding new libraries. We have even been improving basic core object infrastructure and starting to merge libraries together into a single source tree to improve build usability. We have been trying to polish off odds and ends on E17 and fix a slew of bugs and complete unfinished features.
We have been busy. Since the start of this year alone we've put over 11,000 commits into our source repository, released 16 libraries and tools twice in major releases (1.2 and 1.7) and even put in some bugfix releases too of these libraries.
The H: E17 is coming out "when its done". What do you define as done?
CH: We have had a public TODO list published for a long time. We will release when the list is complete (which it pretty much is) and the quality is up to scratch. And by “quality” I mean we have no major bugs (that we know how to reproduce), the features are usable, and the WM is not a total mystery to use.