Given the input sentence, please extract the subject and object containing a certain relation in the sentence according to the following relation types, in the format of "relation1: word1, word2; relation2: word3, word4". Relations include: product/material produced; manufacturer; distributed by; industry; position held; original broadcaster; owned by; founded by; distribution format; headquarters location; stock exchange; currency; parent organization; chief executive officer; director/manager; owner of; operator; member of; employer; chairperson; platform; subsidiary; legal form; publisher; developer; brand; business division; location of formation; creator.

Both Apple Inc.'s AAPL, +2.55% iOS and Microsoft's Windows are expected to gain market share over the next few years, while Google Inc.'s GOOGL, +4.16% GOOG, +4.20% is expected to decline slightly, according to IDC.

Answer: platform: share, Windows