The Seattle-based software developer Ian Kelling is doing “free and open source development for fun”.
;; Works out of the box with csv exported from Thunderbird, Gmail, ;; Linkedin, Outlook.com/hotmail, and probably others. ;; Easily extensible to handle new formats.
Earlier today, I used it to painlessly update a large number of contacts freshly exported into a CSV file.
This is for those of us that do not want to distribute everything in a multitude of cloud services. Let alone leave it in someone else’s garage.