Paxos is a regulated financial company specializing in providing blockchain trust and custodial services for their clients. Paxos' settlement platform (Bankchain) is designed to be integrated with existing systems and to eliminate settlement risk in the exchange of digital assets. The company created a USD backed stablecoin called PAX, that is built on the Ethereum blockchain, and is meant to assist their clients in converting a variety of assets into digital versions, that can be more easily exchanged on a blockchain.

TrueUSD is a stablecoin backed by USD. It was created by TrustToken, a company that specializes in creating asset-backed tokens on the Ethereum blockchain. TrueUSD is fully collateralized and is transparently verified by third-party attestations.
TrueUSD was created within a legal framework that enables users to exchange USD directly with an escrow account. The platform is powered by smart contracts that ensure a 1:1 parity between USD and TrueUSD. Escrow accounts and regulatory compliance practices enable auditing and more legal protection for token holders.
Users wire funds to these third-party escrow accounts, and an equivalent amount of TUSD is generated to their ethereum addresses. Each TUSD can be redeemed for one US Dollar, that is held in escrow.

Dignity is a stablecoin pegged to gold, that was developed by the company Cryptobontix. Each DIG token is pegged to the worth of 0.02445 grams of gold, which was worth exactly $1.00 at the time of the Dignity whitepaper.
Cryptobontix's portfolio of stablecoins are based on a partnership with bullion suppliers. Each individual token acts as a security on a 15-year convertible mortgage. The DIG token is pegged to the value of gold. Every year, 1/15th of the tokens can be redeemed for gold valued at around $1.00.
Cryptobontix does not actually own all of the physical gold. The company plans on spending its profits on acquiring the actual bullion that token holders will have the option of converting.