When you search for "esxi 5.5 license key github," you aren't finding official VMware repositories. You are entering the "gray market" of code hosting.
A: Ethically and legally, yes. Technically? Broadcom is unlikely to sue a hobbyist in their basement. However, you are still violating the EULA. The bigger risk is malware and lack of updates. esxi 5.5 license key github