"They had no concept of a duty of care to their users."

Marcin Wichary recounts a Mastodon thread by computer scientist David Chisnall about vim’s “persistent undo,” a feature that preserves undo history across reboots and long gaps in editing. Chisnall, a longtime vim user, describes how NeoVim - a fork - changed the on-disk format for undo files, silently deleted existing undo files and replaced them with ones vim couldn’t read, erasing years of recoverable edit history. When he raised the issue, NeoVim developers responded that the persistent-undo format was unstable and users should not depend on it. That response, more than the bug itself, convinced Chisnall that the project lacked a duty of care toward users’ data and lost his trust.

Wichary emphasizes why this matters: persistent undo is an unexpectedly powerful safeguard and people vividly remember when software destroys their work. He highlights the damage done by an attitude that treats user data as disposable and cites Jef Raskin’s humane-interface principles - that software should not harm users’ work, should avoid wasting their time, and should be considerate of human frailty - as the right yardstick for evaluating design and development choices. The piece argues that protecting user work is a core responsibility of software craft.