Visual Studio
Short Cuts
close files: CTRL + F4
comment: CTRL + K, CTRL + C
uncomment: CTRL + K, CTRL + U
https://blogs.msdn.microsoft.com/zainnab/2010/04/13/comment-and-uncomment-code/
https://jeremybytes.blogspot.jp/2015/12/visual-studio-shortcuts-comment.html
Extensions
ReSharper
https://www.jetbrains.com/resharper/