Today, ironically your choices for relatively straightforward messaging on the PC/Mac are: iMessage (Mac only), Skype for Business (the consumer client is too distracting for words), Whatsapp Web, or go with a "heavyweight" website/app like Slack (which is painful if all you want is IM and none of Slack's extra features).
R. Fiedler, and C. Kaner. Conference of the Association for Software Testing. Colorado Springs, CO. http://www. kaner. com/pdfs/FiedlerKanerCast2009. pdf, (2009)
X. Qi, Q. Yang, D. Nguyen, and G. Zhou. Proceedings of the 2013 ACM Conference on Pervasive and Ubiquitous Computing Adjunct Publication, page 111--114. New York, NY, USA, ACM, (2013)
A. Albin-Clark. ITiCSE '08: Proceedings of the 13th annual conference on Innovation and technology in computer science education, page 153-157. New York, NY, USA, ACM, (2008)