World Weaver
The current version of World Weaver works as standalone in the browser, and as such basically costs me nothing to host. This comes however with a few limitations, namely the fact that as you store everything locally, sharing and collaborative edition is not possible.
There will probably be a paid version at some point, because implementing those features require server bandwidth. A few premium features might arise at some point, but we have no plan for it yet
But here's what's important: we are committed to provide a free, usable version. You will always be able to create universes locally with no item count limitation.