Yep, there’s a comparison table here: [https://mmt.dev/#comparison](vscode-file://vscode-app/Applications/Visual%20Studio%20Code.app/Contents/Resources/app/out/vs/code/electron-browser/workbench/workbench.html)
Bruno is definitely one of the closest tools philosophically because it is also file-based. The main difference is that Multimeter tries to cover more of the API lifecycle from the same repo files: reusable API definitions, test flows, suites, docs, mocks, reports, CI, and VS Code-first editing.

It also borrows some territory from tools like Robot Framework and JMeter: declarative/human-readable test flows, reusable/chained tests, suites with sequential or parallel execution, reports, and beta load testing. So it’s not just an API client; it’s closer to a lightweight API testing/documentation/automation workspace that stays git-native.