Over the course of bitcoin's two-year scaling debate, a few major alternatives have grown to challenge the network's most popular and longest-running software, Bitcoin Core.

Among the more notable efforts have been Bitcoin XT and Bitcoin Classic, which prioritized support larger block sizes as a method to support more transactions. However, a side effect of their ambitious aims was that network users would need switch implementations to enact the changes, and not everyone has wanted to do so.

The development exposes one of the more curious aspects of the scaling debate, as alternative solutions have needed to propose both a technical change – and build their own developer team – as part of their bids to put forth differing ideas.

One of the main criticisms of Bitcoin Unlimited, one recently popular alternative that allows miners and users to flag support for the block size they want, is that the code is buggy – or, at least, not yet mature. For example, in March, attackers were able to exploited two such bugs, causing most of the network nodes running the software to temporarily shut down each time.

In this light, the emergence of an implementation called 'Bcoin' (built by bitcoin startup Purse) to the debate could be a notable development in the scaling saga.

The software project got a recent boost this week when it introduced its own take on an old scaling idea, 'extension blocks' (or 'e-blocks'), which the company painted as a way for getting around today's block-size standstill.

The idea is controversial, as evidenced by complex technical discussion following the announcement, with some developers arguing that e-blocks would be an insecure addition.

Still, e-blocks have still seen a strong showing of support, in large part due to the perceived proficiency of its team. And, notably, Bitcoin Unlimited supporters have so far had favorable things to say about the project.

Haipo Yang, chief executive of mining firm ViaBTC, for instance, told CoinDesk that he supports Purse's concept and the Bcoin team.

Yang said:

Overall, the argument is developing that Bcoin, an alternative Node.js implementation that launched in September, boasts a stronger technical team than that of Bitcoin Unlimited and other so-called 'big block' teams.

Purse CTO and Bcoin developer Christopher Jeffrey, for example, has been praised for architecting the software, as well as an in-progress Lightning implementation called Plasma that could be layered on top.

Meanwhile, Joseph Poon, Lightning Network co-creator, helped author the specification for the Bcoin implementation’s recently introduced flagship tech.

One example of trust in the competence of the team, supporters argue, is that mining pool BTC.com has already mined one block while running the software in March – allegedly a first for a client not based on bitcoin's original code implementation.

Purse has released a specification draft and reference implementation code that implements extension blocks on top of Bcoin.

That's not to say that Bcoin wants to offer a replacement for Bitcoin Core, as has been suggested for other implementations. When first introduced, it was described by the company as a bitcoin alternative with cleaner code that could co-exist alongside other software versions.

Despite Yang's confidence, however, not all Bitcoin Unlimited supporters are going all in on extension blocks.

Former Bitcoin Foundation board member Olivier Janssens, for example, criticized the solution for its complexities, telling CoinDesk Bcoin's idea was "way too complicated".

"People need to get over their fear of hard forks," he said.

Still, many are saying positive things about the solution, even if they're possibly more focused on other scaling options.

"I like extension blocks, but I think there is almost no risk from making the actual blocks bigger, too," bitcoin investor and Bitcoin.com operator Roger Ver, one of the most vocal advocates for Bitcoin Core alternatives, told CoinDesk.

Bitcoin Unlimited developer David Jerry Chan went so far as to compare the tech favorably to other available solutions.

"I see the proposal as a reasonable and better alternative than SegWit," he said.

Chan went on to say that Bitcoin Unlimited developers are still discussing the proposal, and there's no "official opinion" from the team as yet.

As far as potential setbacks go, however, one of the criticisms of Bcoin is that it needs time to review, no matter the merits of its team. (SegWit, for example, was reviewed and tested for roughly a year before release.)

On the other hand, Purse CEO Andrew Lee has argued that the Bcoin code is already live, so it could take less time to review.

Indeed, according to the technology announcement, the next steps are to deploy it on the bitcoin test network, get further review, and wrap up the specification.

Yang agreed, concluding:

Pencils image via Shutterstock