Blockstream is a private, for profit, blockchain technology company, that has played a key role in helping to develop, and fund, many of the key features of the Bitcoin Core platform. Blockstream is focused on developing bitcoin applications and has raised significant funding from several large investment funds. The company also employs several developers that are very influential within the Bitcoin Core development project. This, as well as being of Bitcoin's largest donors, has led to some criticism about conflicts of interest.
Blockstream is developing a number of Bitcoin applications that are intended to encourage adoption and improve transaction times on the bitcoin network. Their primary focus is on Sidechains, which are are extensions to existing blockchains that improve their functionality. The company is also working closely with industry leaders to create the Bitcoin Lightning system that will support higher trading volume and faster transactions on the bitcoin network. Blockstream is also developing a data feed, satellite network, and other applications that they hope will make blockchain more accessible.

Emercoin is a blockchain-based development platform. It has developed a range of easy-to-use dSDKs (Decentralized Software Development Kits) that can be used to more easily build DApps. This set of software development tools allow the creation of blockchain-based software and services.
Emercoin's dSDKs have been implemented in several innovative DApps and provide developers with solutions for a variety of functionalities. Some of the dSDK's that Emercoin offers are specifically geared for decentralized DNS, SSH, SSL, and DPO solutions.
Emercoin has a hybrid consensus mechanism that combines elements of Proof-of-Stake (PoS) with a Proof-of-Work (PoW) algorithm that is merge-mined with Bitcoin. The network is powered by the EMC coin.

High Performance Blockchain (HPB) is a Chinese company that is developing an improved blockchain infrastructure. Their goal is to dramatically improve the speed of transactions and throughput of existing blockchain systems. HPB has been called the EOS of China.
Similar to EOS, HPB uses a delegated Proof of Stake (DPoS) consensus algorithm that will enable parallel processing. It will also aid in improving the performance of their blockchain, and they hope that it will enable the creation of an ecosystem for the creation of decentralized applications.
HPB's platform is based on hardware accelerator chip drivers. The accelerator chips can be customized and will aid in the performance of the blockchain. HPB has the ambitious goal of enabling 1 million transactions per second.
The company's founders are well connected in the blockchain and payment sector in China. NEO is one of the chief investors in the company, and they also works with Union Pay; which is an influential payment network that connects banks in China.