Which cryptocurrency server software supports the walletnotify feature? I am looking to build a realtime service for crypto payments and would like to know which currencies are based on server software that supports "walletnotify" out of the box in the way Bitcoin does - specify the script to run on payment received and confirmed.

Am I correct to assume BCH, BCG and LTC support this since they are forks of the Bitcoin code?

What are other cryptocurrencies I should look at?
Yeah, All bitcoin forks support walletnotfiy.

most digital-currencies have a walletnotfiy with some a few code changes.

that's a list of all Bitcoin forks