High Quality Content by WIKIPEDIA articles! VIM (Vendor Independent Messaging) was a standard API for applications to integrate with e-mail on Windows 3.x, proposed by Lotus, Borland, IBM Novell in the early 1990s. Its main competitor was Microsoft`s MAPI, which was the eventual winner of the MAPI v. VIM war. Ultimately, the choice of VIM or MAPI did not make a huge differences: bridges meant that an MAPI client could access a VIM provider and vice versa, and the rise of Internet e-mail in the mid-1990s rendered the panoply of proprietary e-mail systems which VIM and MAPI were meant to cater to largely irrelevant.