Whitespace.
See who already built your idea — and the space they left open.

CLUSTER BOOKING-CALENDAR-CUSTOM · 4 ENTRIES · EARLIEST ENTRY 2026-10-09

Self-hosted email and calendar suites

This cluster consists of self-hosted email and calendar suites for custom domains, covering mailbox management, message exchange with attachments, event scheduling, and public booking pages. The cluster's dated history is too thin to read a shape from—it predates the index or its members are undated. On traction, mailflare leads, though its measured activity signals are at zero.

Entry timeline

ENTRY TIMELINE

OCT 2026: 4
OCT 2026

Each bar is the month a member carries, which is a creation date where the source published one and a crawl date otherwise. Nothing in the index was found before 11 August 2026, and coverage broadened sharply on 14–15 August, so a bar from then on reports how much we found that month, not how much was built; an earlier bar reports how far back a member's own source dated it — not how long we have been watching.

Members by activity

Activity signals, not revenue.

Build origin · 4 unlabelled

Operator · 1 open source · 3 unlabelled

Two labels per entry, never collapsed into one: how it was built, and who stands behind it. Counted over the 4 listed below. Unlabelled means nothing has decided yet — not that the answer is small.

  1. 01mailflare0★12 days—Self-hosted email and calendar suite for custom domains, with shared mailboxes, attachments, automatic replies, and public booking pages.
  2. 02mailflare0★11 days—Self-hosted email and calendar suite for custom domains that lets users manage mailboxes, exchange messages with attachments, schedule events, and share booking pages.
  3. 03mailflare0★12 days—Self-hosted email and calendar suite for custom domains that lets users manage mailboxes, exchange messages with attachments, schedule events, and share booking pages.
  4. 04mailflare0★12 days—open sourceSelf-hosted email and calendar suite for custom domains that lets users manage mailboxes, send and receive mail, and share booking pages.

Ranked by traction, highest first, and paged 20 at a time — this is a window on the cluster, never the whole of it. Ties are broken by a stable id so a product cannot appear on two pages or fall between them. Browse every cluster.