Iceberg's https:// clones, fetches, pulls and pushes, and Metacello's github:// loads, go to this CORS proxy: each request goes to the proxy's URL followed by the host and the path of the repository, such as github.com/pharo-project/pharo.git. The proxy sees the code and any credentials that pass through it, so choose only one that you run or trust: the user name and token that a push asks for go only through My proxy, or straight to the host with None, never through the site's default. With None, the requests go to the repository itself, which works only for a server that lets this page in (CORS). This browser keeps your choice; a link cannot set it.