Both Billion Mail and Postal show comparable community engagement with 15,408 and 16,724 stars respectively. In terms of developer contributions, Billion Mail has 1,666 forks, indicating strong developer engagement.

Billion Mail is growing faster, adding 100 stars in the last 30 days (+0.7%) against adding 58 stars for Postal (+0.3%). Billion Mail is the smaller project of the two, so it is closing the gap rather than extending a lead.

Postal shows more recent development activity with its last commit 7 days ago, while Billion Mail was last updated 2 months ago. This suggests Postal is being more actively maintained.

Both tools share common technology foundations, being built with JavaScript, Bash, SCSS. However, they differ in their additional technology choices: Billion Mail uses CSS, Typescript, JSX, Golang, Vue, PHP while Postal leverages Ruby, CoffeeScript.

Postal has been in development longer, starting 9 years ago, compared to Billion Mail which began 1 year ago. This 7.9-year head start suggests Postal may have more mature features and established processes.

Postal uses the MIT license, which is more permissive than Billion Mail's AGPL-3.0 license, potentially offering greater flexibility for commercial use and integration.

Both tools serve similar use cases in Email Marketing & Newsletters. However, they also have distinct specializations: Postal extends into Email Platforms.

Both Billion Mail and Postal offer self-hosting capabilities, giving you full control over your data and infrastructure.