head to head · open source
Billion Mail vs roapi
Billion Mail has 15,619 GitHub stars, 1,704 forks, 236 open issues and last shipped 3 months ago. roapi has 3,434 stars, 209 forks, 66 open issues and last shipped 6 months ago. Billion Mail leads on adoption by 355% (15,619 vs 3,434 stars). Billion Mail is written in Go under AGPL-3.0; roapi is written in Rust under Apache-2.0. Billion Mail has attracted 11% as many forks as stars, roapi 6%. Billion Mail was the more recently maintained of the two, and both are self-hostable with no licence fee.
Two open source projects, one decision. Both are free and self-hostable — the differences are community size, license terms, language stack and release pace.
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Side by side
| Billion Mail | roapi | |
|---|---|---|
| GitHub stars | ★ 16K | ★ 3.4K |
| License | AGPL-3.0 | Apache-2.0 |
| Written in | Go | Rust |
| Last push | 2026-06-11 | 2026-03-25 |
| Forks | ⑂ 1.7K | ⑂ 209 |
| Self-hosting | Yes | Yes |
| Data ownership | Your server | Your server |
pick Billion Mail if
- You weight community size — 16K stars and counting
- You want the AGPL-3.0 license terms
- Your stack matches Go
- You value the larger contributor base for long-term maintenance
pick roapi if
- You want the roapi feature set and don't need the biggest community
- You prefer the Apache-2.0 license terms
- Your stack matches Rust
- You evaluated both and roapi fits your workflow better
About Billion Mail
BillionMail is an open source mail server and email marketing platform written in Go and released under the AGPL 3.0 license. It lives in the self hosted email ecosystem and is described as a solution for newsletters, promotional emails, and transactional messages. The project combines mail server topics such as Postfix, Dovecot, Rspamd, and SMTP with campaign features such as customer management, analytics, templates, and sending control.
read the full Billion Mail overview →
About roapi
ROAPI is a Rust based, Apache 2.0 licensed server that turns static and slowly changing datasets into read only SQL, FlightSQL, GraphQL and REST APIs without requiring a single line of application code, and it is built for data engineers, analysts and developers who need to publish Parquet, CSV, JSON or database tables as queryable endpoints quickly.
read the full roapi overview →
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Frequently asked questions
Is Billion Mail or roapi more popular?
Billion Mail has 15,619 GitHub stars and roapi has 3,434. Billion Mail has the larger community by that measure.
Are Billion Mail and roapi free?
Both are open source. Billion Mail is licensed under AGPL-3.0 and roapi under Apache-2.0. Neither carries a licence fee.
What is the difference between Billion Mail and roapi?
Billion Mail is written in Go and roapi in Rust. The practical differences are community size, licence terms, language stack and release cadence — all compared in the table above.
Which should I choose, Billion Mail or roapi?
Choose Billion Mail if you want the larger community (15,619 stars) or its AGPL-3.0 licence terms. Choose roapi if its feature set, stack or Apache-2.0 licence fits better. Both are self-hostable.