If the definition of a PIM is where all your notes, appointments, tasks and contacts are stored but more than that, linked then I have not found any PIM available in Linux. I have to use Windows XP under Virtual box and that is slow. I need to look at a task linked to a contact, recall all communication with that contact so all tasks, calls, letters should be linked.
I have tried Kontact (keeps throwing errors and seems susceptible to all sorts of minor changes from software updates etc) This does not meet the definition and Evolution does not either. Chandler has no contact module. None of these have tasks/appts. directly linked to contacts
Under Windows we have Chaos, great little app. and at the top end Act! for Windows, and of course Outlook and my favorite is Netmanage Ecco which will run under WINE. However Ecco was to me as a project manager the best of the lot and I started using it in 1993 then Netmanage bought it and stopped development in 1998? This has now lost its integration functionality as everything else has moved on but it did run under Windows 3.1 in 256k was reliable, easy to network, share and synchronise. Even Packrat 4.1 would be nice.
If someone is listening Ecco would be great to develop under linux. Or does someone know of of a comprehensive simple app that does not require 2 days of setting up apache servers etc?