The other blockchain based domain is .eth, which can only be purchased through a bid system. NEM also has a similar concept called "namespaces" but is quite different from .eth and .zil in functionality.
Blockchain based domains will have limited use because they are limited to the base currencies (in this case eth and zil), though that will change when atomic swaps become mainstream.
Thanks @bunnychum.
I completely agree with you @devann
This is just yet another domain name solution based on blockchain. What makes it more interesting that these domains can be used to host a website. other than namecoin, zilliqa has started another DNS system on top of ethereum. Could be a good solution for web developers to handle ETH transactions.
However, using domain names just as a wallet to send and receive payments is something that comes along.
There is much more to these decentralized names. There is a W3C community group working on decentralized identifiers (DIDs), the DID foundation, the reboot web of trust events,..
You can find 24+ different decentralized identity providers already. See the w3c registry: https://w3c-ccg.github.io/did-method-registry/#the-registry
I would say blockstack.org is one of the leading players in the decentralized domain name system.
Thanks for the info @friedger. The 24+ DIDs are provisional, which means they are not available yet.