I read a lot of e-books. The process by which I do this is as follows: get an ePub from somewhere (Project Gutenberg, as ever, is a pretty rich source of books, and most of their stuff is available in ePub format), and add that book into Calibre. I marked my Calibre ebook library as synced with Ubuntu One, so every time I add a book it’s uploaded to the cloud so I never lose it. Then I use Ubuntu One for N9 to save the book onto my phone, and FBReader automatically picks that up and lets me read it.
Up until today, though, one of the things I didn’t like about this little process was that Calibre just looks rather awful. Calibre, the Swiss Army knife of e-book management, does everything. It catalogues your books, fetches correct metadata for them, lets you edit and rate and fix and fiddle them, and a whole heap of stuff that I don’t use but that other people do like automatically downloading news and turning it into a book, syncing to devices like a phone or kindle (I use U1 for that), integrate with websites, and so on. But… it looks kinda disorganised and all over the place, and that makes me sad. The Calibre team have been pretty clear that to them, Calibre is a pro-level tool and so any UI reorganisation which involves hiding half the functions is not likely to pass muster; having said this, I’m fairly sure that if someone rocked up with a fantastic new UI and was prepared to commit to working on it or guiding development, they’d get a decent hearing; Kovid Goyal, the lead developer, is ludicrously fast and responsive to requests for changes. Now, I’m not a visual designer; I’m not a designer at all, either, so changing the overall user experience of the app isn’t something I can credibly do. But I do know what I personally like, which is stripped-down simple apps.
So for me, Calibre looks like this…

…which, to my eyes, looks a lot neater. Doing this just requires poking at Calibre’s configuration a bit.
First, turn on the Cover Browser with the “arrow” button in the status bar next to “Jobs”. Then, turn off the Tag Browser and Book Details view with the other two buttons, and drag the divider between the Cover Browser and the book list downwards so that the book list is hidden. Next, in Preferences > Toolbar, customise the menu bar and add whatever you want to it. Calibre ships by default with the menu bar empty on Linux (but populated on OS X); here, we add the functions you care about to the menu (which works correctly on Ubuntu as a menu in the Unity top bar). Be sure and add “Preferences” to the menu! Finally, also in Preferences > Toolbar, edit the main toolbar and remove everything from it (so it disappears). At that point, you’ve got a super-stripped-down Calibre which still does everything you want but looks fairly slick. Make whatever other changes you deem necessary!
At the moment it is sadly not possible to “export” your Calibre configuration (so that people can swap configs around, which would make it easy to test different ones and possibly make it easier to create a “calibre-light” package for not-quite-as-pro-as-Pro-users which is still full Calibre but a bit less button-heavy and intimidating. It’d be pretty cool if that were possible; I’ve seen people talking about it on the Calibre forums. Nonetheless, a bit of tweaking can make a powerful app also be a pleasant-looking app, and you lose nothing in the way of features; maybe Calibre with a nicer default UI could be a flagship app for the Ubuntu desktop?
I think you’ve stepped on an interesting point that was recently raised also on HackerNews: you favour a visual approach to data, whereas “pro hackers” like Kovid favour data density.
Me, I would hate your Calibre arrangement — scrolling one book at a time? That’s as inefficient as browsing a physical shelf! But I’m sure people like my wife (who loves Pinterest, aka “Delicious with pictures”) would probably love it.
There’s a bit of a disconnect there, and it’s important to remember that in most cases, one size doesn’t fit all. It’s important to have options for people who favour data-density as well as for people who favour simpler visuals.
Giacomo: you are entirely right. One thing I’ve discovered is that it ought to be possible to build a new UI on calibre’s underlying infrastructure, meaning that there’d be a separate app for people like me who prefer visual approach to data but it’d still have all the Calibre excellence, because Kovid and the team have tried very hard indeed to make all calibre’s functions available without needing the gui.
I should note that I don’t browse one book at a time — I use the search a lot
I wish it were instant. That’s the sort of thing I’d do in an alternative UI. Might write one.