# SETI@home volunteer launch

> A volunteer screensaver drew over 1 million signups within three months.

- Owner: UC Berkeley SETI@home team
- Kind: App & software
- Sector: Education
- Seed date: 1999-05-17
- Milestone date: 1999-08-16
- Date basis: Documented milestone; not a measured attention peak.
- Spread Score: 10 (Niche, provisional), v1.2
- Mechanics: Visible in use, Platform jump, Press loop

## Summary

SETI@home turned idle computers into scientific volunteers. Berkeley documented adoption in offices and classrooms, while competing teams gave participants a shared identity and public progress to follow.

## Timeline

- 1998-11-20 — SETI@home beta testers (Open web) — A 100-user beta began analyzing real telescope data.
- 1999-05-17 — UC Berkeley (Open web) — SETI@home launched publicly as a volunteer computing screensaver.
- 1999-05-19 — UC Berkeley (Open web) — Reported over 200,000 downloaders since May 17 and volunteers helping with programming, web pages and translation.

The full timeline, metrics and sources are on the case page, or via the Pro API (https://howitspread.com/developers).

Canonical URL: https://howitspread.com/cases/seti-at-home-volunteer-launch

Cite as: How It Spread (2026). “SETI@home volunteer launch.” Case HIS-01106. Spread Score v1.2: 10/100. Updated 2026-10-17. https://howitspread.com/id/HIS-01106