| Price from | €200/mo | $10/mo |
| Free plan | Yes | Yes |
| Free trial | — | — |
| Open source | — | — |
| Web | — | Yes |
| Windows | Yes | Yes |
| macOS | Yes | — |
| Linux | Yes | Yes |
| API | Yes | Yes |
| Self-hosted | Yes | Yes |
| Plans published | 3 | 2 |
| Spec score · Chat APIs | 8.7 (#2) | 8.4 (#4) |
| Product | ejabberd is an open-source server for XMPP messaging, MQTT, SIP, and Matrix. | Emitter is a real-time publish-subscribe messaging service for connecting online devices. |
| Protocols | The product supports XMPP extensions including MUC, MAM, PubSub, Carbons, Push, and OMEMO. | Emitter supports MQTT and binary or text messages over WebSockets. |
| Security | The maker describes TLS 1.3, modern cipher suites, SASL with SCRAM-SHA-256, and OMEMO end-to-end encryption as available on a fresh install. | The maker says Emitter supports per-channel authorization policies and SSL/TLS, encrypts network traffic, and does not inspect messages. |
| Support | Community Server includes community forums and documentation, while Business Edition and Fluux include direct ProcessOne support and LTS releases. | The maker offers support contracts and directs questions to [email protected] and GitHub issues. |
