There are plenty alternatives to Open-Registry, probably the most famous is the npm registry by the company npm inc.

Most differences in the listed alternatives is about performance and governance.

For performance differences between the different registries, please look at the benchmark results from https://github.com/open-services/public-registry-benchmarks

Name	Governance	Geographic Location
Open-Registry	Community Owned	EU
npm Registry	For-profit Company	US
node-modules.io Registry	Individual	US
cnpmjs.org Registry	Unclear	China?
js-ipfs Registry	For-profit Company	US

In general, it's easy to switch to any alternatives on this list. Simply run npm config set registry $registry-url in your terminal, replacing $registry-url with the URL to the registry.