Jos wrote a blog post yesterday commenting on the complexity of the PIM problem. He raises an interesting concern about whether we would be all better if there was no Trojitá and I just improved KMail instead. As usual, the matter is more complicated than it might seem on a first sight.
Executive Summary: I tried working with KDEPIM. The KDEPIM IMAP stack required a total rewrite in order to be useful. At the time I started, Akonadi did not exist. The rewrite has been done, and Trojitá is the result. It is up to the Akonadi developers to use Trojitá's IMAP implementation if they are interested; it is modular enough.
People might wonder why Trojitá exists at all. I started working on it because I wasn't happy with how the mail clients performed back in 2006. The supported features were severely limited, the speed was horrible. After studying the IMAP protocol, it became obvious that the reason for this slowness is the rather stupid way in which the contemporary clients treated the remote mail store. Yes, it's really a very dumb idea to load tens of thousands of messages when opening a mailbox for the first time. Nope, it does not make sense to block the GUI until you fetch that 15MB mail over a slow and capped cell phone connection. Yes, you can do better with IMAP, and the possibility has been there for years. The problem is that the clients were not using the IMAP protocol in an efficient manner.
It is not easy to retrofit a decent IMAP support into an existing client. There could be numerous code paths which just assume that everything happens synchronously and block the GUI when the data are stuck on the wire for some reason. Doing this properly, fetching just the required data and doing all that in an asynchronous manner is not easy -- but it's doable nonetheless. It requires huge changes to the overall architecture of the legacy applications, however.
Give Trojitá a try now and see how fast it is. I'm serious here -- Trojitá opens a mailbox with tens of thousands of messages in a fraction of second. Try to open a big e-mail with vacation pictures from your relatives over a slow link -- you will see the important textual part pop up immediately with the images being loaded in the background, not disturbing your work. Now try to do the same in your favorite e-mail client -- if it's as fast as Trojitá, congratulations. If not, perhaps you should switch.
Right now, the IMAP support in Trojitá is way more advanced than what is shipped in Geary or KDE PIM -- and it is this solid foundation which leads to Trojitá's performance. What needs work now is polishing the GUI and making it play well with the rest of a users' system. I don't care whether this polishing means improving Trojitá's GUI iteratively or whether its IMAP support gets used as a library in, say, KMail -- both would be very succesfull outcomes. It would be terrific to somehow combine the nice, polished UI of the more established e-mail clients with the IMAP engine from Trojitá. There is a GSoC proposal for integrating Trojitá into KDE's Kontact -- but for it to succeed, people from other projects must get involved as well. I have put seven years of my time into making the IMAP support rock; I would not be able to achieve the same if I was improving KMail instead. I don't need a fast KMail, I need a great e-mail client. Trojitá works well enough for me.
Oh, and there's also a currently running fundraiser for better address book integration in Trojitá. We are not asking for $ 100k, we are asking for $ 199. Let's see how many people are willing to put the money where their mouth is and actually do something to help the PIM on a free desktop. Patches and donations are both equally welcome. Actually, not really -- great patches are much more appreciated. Because Jos is right -- it takes a lot of work to produce great software, and things get better when there are more poeple working towards their common goal together.
Update: it looks like my choice of kickstarter platform was rather poor, catincan apparently doesn't accept PayPal :(. There's the possiblity of direct donations over SourceForge/PayPal -- please keep in mind that these will be charged even if less donors pledge to the idea.