Mozilla started the list in 2007, and major browsers bundle it.
The list helps browsers reject cookie scopes that would cross between unrelated tenants on a shared domain. ngrok gives ngrok.pizza as an example: a site at yummy.ngrok.pizza cannot set a cookie for ngrok.pizza that another tenant, such as scrumptious.ngrok.pizza, could receive. The company says the list contains more than 10,000 rules and is also used by services including GitHub Pages and Vercel.
According to ngrok, a small volunteer maintainer group has handled a record number of pull requests this year, with most closed without merging. Maintainers are publicly debating whether entry criteria should become easier or stricter, and one longtime maintainer describes the workload as approaching a breaking point.
The post does not announce a PSL policy change, quantify the pull-request volume, or establish that a governance reform will be adopted.