In Forrester's evaluation of the emerging market for function-as-a-service (FaaS), we identified the nine most significant providers in the category — Alibaba, Amazon, Cloudflare, Google, IBM, Microsoft, Nimbella, Oracle, and Tencent — and evaluated them. This report details our findings about how well each vendor scored against 10 criteria and where they stand in relation to each other. Application development and delivery (AD&D) professionals can use this review to select the right partner for their FaaS needs.