Creator here. A few key differences:

1. from isolation pov, Matchlock launch Firecracker microvm with its own kernel, so you get hardware-level isolation rather than bubblewrap's seccomp/namespace approach, therefore a sandbox escape would require a VM breakout.

2. Matchlock intercepts and controls all network traffic by default, with deny-all networking and domain allowlisting. Bubblewrap doesn't provide this, which is how exfiltration attacks like the one recently demonstrated against Claude co-work (https://www.promptarmor.com/resources/claude-cowork-exfiltra...).

3. You can use any Docker/OCI image and even build one, so the dev experience is seamless if you are using docker-container-ish dev workflow.

4. The sandboxes are programmable, as Matchlock exposes a JSON-RPC-based SDK (Go and Python) for launching and controlling VMs programmatically, which gives you finer-grained control for more complex use cases.