Emacs

Shame on every user who downvoted the parent comment. Zero-effort questions like this are akin to panhandling, i.e. "To accost people in a public place and ask for [links to easily searched-for web pages]"--to refuse to help oneself and lazily demand to be spoon-fed by others.

As the guide says, "Community standards do not maintain themselves: They're maintained by people actively applying them, visibly, in public. ... There have been hacker forums where, out of some misguided sense of hyper-courtesy, participants are banned from posting any fault-finding with another's posts, and told “Don't say anything if you're unwilling to help the user.” The resulting departure of clueful participants to elsewhere causes them to descend into meaningless babble and become useless as technical forums."