STRATO uses an Ethereum client written in Haskell.

Open source https://github.com/blockapps/ethereum-vm is forked from a repo which says:

This package provides a tool written in Haskell to allow you to connect to the Ethereum blockchain

At the lower left of http://blockapps.net there is a link to RESTful API Documentation.

STRATO uses an Ethereum client written in Haskell.

Open source https://github.com/blockapps/ethereum-vm is forked from a repo which says:

This package provides a tool written in Haskell to allow you to connect to the Ethereum blockchain

At the lower left of http://blockapps.net there is a link to RESTful API Documentation. Depending on what you need from an Ethereum client, it may work and it lists resources such as:

/account
/block
/transaction
/storage