If you needed another sign that we're living in a multi-blockchain world, Circle's latest product reveal might have been it.

Overshadowed by the clamor surrounding the startup's decision to end consumer bitcoin services, it was almost lost that it announced it would soon open-source a smart contracts platform it described as an "evolution" of its core transaction processing.

Called 'Spark', Circle's new tech isn't a blockchain or a new cryptocurrency. Rather, as explained by the company, it uses a combination of bitcoin, other blockchains and traditional settlement rails to further its mission of promoting a global, social payments platform.

Still, Circle co-founder and president Sean Neville explained that, for all the backlash the company has so far received, Spark doesn't exactly mark a shift in its vision so much as a refinement of how it will execute on it.

Neville told CoinDesk:

In other words, transactions would still settle in bitcoin, though Spark could also allow Circle and its money transfer partners to use other networks, whether that’s a separate blockchain network (like ethereum) or a traditional card settlement network (like ACH).

"Bitcoin can be used with Spark today, and other distributed ledgers can also be plugged into it. Traditional private systems can also be added as integrations," he said.

As explained by Neville, the company has (and continues to see) bitcoin as a protocol more akin to TCP/IP, one of the lower-level, foundational Internet protocols. (He compared Spark to a HTTPS, a top-level protocol that relies on TCP/IP as a base layer).

In this light, Neville described Spark as an application designed to run on top of any blockchain or distributed ledger, stating that it could even be compatible with permissioned blockchain technologies such as IBM's Fabric or R3's newly introduced Corda system.

Neville suggested that this increased functionality would perhaps better allow its transfer network expand to serve more consumers.

"We are still using bitcoin. We still trade in it, and use it to support the global consumer payment service we're offering. We're just no longer supporting the buying and selling of it as an exchange product," Neville said.

So, what's missing from the bitcoin protocol?

In Circle’s view, Neville said that Spark is designed for payments firms that would want to use bitcoin to transfer money. This means it offers extra tools designed for know-your-customer (KYC) and anti-money laundering (AML) compliance and exchange rate negotiation.

"Spark includes protocols and support for workflow rules, identity, regulatory compliance and exchange rate information, among other things, that we've added to support settlement on blockchains and other rails," he continued.

Neville said that Circle had hoped the official bitcoin software would perhaps one day be designed with these features, but that he understands that they don't fit into bitcoin's roadmap and why they shouldn't be included or prioritized in the protocol.

Nonetheless, in statements to The Wall Street Journal, Circle CEO Jeremy Allaire expanded on this critique, asserting that the lack of governance around bitcoin software management was also a factor in influencing its decision.

"We've been deeply frustrated with that lack of progress, and we want to move it forward," Allaire told the news source.

The added functionality also hints at the design behind Spark.

Faced with the prospect of competing against established firms such as PayPal or Venmo, Circle's decision to embrace a platform that could expand on the current bitcoin network, as part of a way to include more banks and FinTech firms, is perhaps not surprising.

In statements to CoinDesk, Circle spoke in similarly broad strokes, calling Spark a "public protocol and API" and an alternative to traditional settlement.

For example, should Circle users want to transfer money to the Philippines, Circle would turn the original funds into bitcoin, which would then be sent overseas to a partner firm like Coins, that would then provide local currency.

As such, Neville was keen to stress that Spark intends to be an "open source project" one that it will seek to manage collaboratively with partners focused on money transfer.

As shown in CoinDesk's Q3 State of Blockchain report, there may be added pressures behind the move given the lack of new bitcoin exchanges seeing investment.

Over the course of 2016, investment in infrastructure-layer bitcoin companies (such as exchanges and wallets) has been on the decline, a trend that has extended to new blockchain networks, with existing bitcoin exchanges extending to new markets.

Spark image via Shutterstock