Domain Namecoin (NMC) is an experimental open source technology that provides similar functions to traditional DNS (domain name management system) service providers, with security, non-censorship, privacy and fast features. Namecoin is the first branch of Bitcoin and one of the most innovative "altcoins". For the first time, merge mining and decentralized DNS functions were implemented.

1. Project application

Namecoin is the first branch of Bitcoin and remains one of the most innovative "altcoins". It first implements merge mining and decentralized DNS. Namecoin is also the first solution for Zooko's Triangle, a long-standing problem of producing a naming system that is simultaneously secure, decentralized and human-relevant. Specific applications are:

•Protect the right to free speech online by making the Internet less censored.
•Attach identity information (such as GPG and OTR keys as well as email, Bitcoin and Bitmessage addresses) to the identity you choose.
•Tor .onion domain with human significance.
•Decentralized TLS (HTTPS) certificate verification and supported by blockchain consensus.
•Use the .bit top-level domain to access the website.
•Proposed ideas such as document signatures, voting, bonds/stocks/stocks, trust networks, notarization services and proof of existence.

2. The relationship between Namecoin and Bitcoin

Namecoin codebase consists of a Bitcoin codebase that changes relatively little (about 400 lines), and other features are built on top of it. The mining process is the same, but the blockchain is separate, so Namecoin is created. This approach is adopted because Bitcoin developers want to focus almost entirely on making Bitcoin a viable currency, while famous currency developers are interested in building naming systems. Since the expected use cases are different between the two projects, consensus and protocol rules may make sense in one aspect and not in the other. Examples of places with different protocols or consensus rules:

•Namecoin's consensus rule requires mandatory uniqueness of names. Although data can be stored in Bitcoin (e.g., key/value pairs in OP_RETURN output), Bitcoin does not enforce uniqueness. In theory, it is possible to build a layer above Bitcoin to discard the output of OP_RETURN that disrespects uniqueness (e.g., name operations that steal other people's names), but miners won't enforce any such layers. If the miner does not enforce the transaction validity rules, PoW will not support it, meaning that the lightweight SPV-based client will not be able to enforce these validity rules.
•Because consumers expect financial transactions to be different from name registration fees, and because global financial transactions differ from global name registrations, the optimal block sizes for Namecoin and Bitcoin may be different.
•In currency, inflation attacks are deadly, while in naming systems, inflation attacks are just spam or crouching attacks: terrible, but hardly deadly dangers. Therefore, decisions between Namecoin and Bitcoin regarding features such as zk-SNARK-based anonymity (which poses the risk of inflationary attacks) may lead to different conclusions.
•Some scripting features that make sense for Namecoin may not make sense for Bitcoin, for example, scriptPubKeys that allow scriptPubKeys to limit any spending transactions. In naming systems, features like this can make updating and updating names more convenient and secure, but in currency, they can compromise substitutability.
•Coinbase's commitment to the name database can be enforced through the Namecoin consensus rule, so that SPV proofs whose names do not exist can be created.
•In general, Namecoin developers try to minimize the patch sets for bitcoin. If a feature is available in Bitcoin, we try to add it to Bitcoin and merge it into Namecoin. Namecoin usually introduces the difference from Bitcoin only if it doesn't make sense to Bitcoin due to its use cases. Although Namecoin can theoretically be used as a general currency, Namecoin developers do not encourage this use case. There are a lot of cryptocurrency projects (such as Bitcoin) that are specifically used for this purpose. If you are looking for currency, you should use one of the items.

Related links:
https://www.namecoin.org/docs/faq/