TryDesync

try.desync.com gives you a web-based shell on a dynamically-allocated instance.

There are some differences from a normal instance, though. Specifically:

• The host is a VM.
• Network connections are limited in terms of concurrency.
• Network traffic is limited in aggregate throughput.
• The Basis image is a customized FreeBSD that includes some tools like curl and mtr.

The session broker (Zuul) places some limits on number of concurrent sessions beyond the normal placement limits imposed by the API, mostly by client ASN and/or subnet. The idea is to prevent one person from hogging all the sessions, which might also indicate that some mischief is afoot.