Not unlike a post-Internet-era Bloomberg Terminal, OpenFin was a startup which joined the revolutionary world of user interfaces to fast-moving information, back in 2010. If you cast your mind back, those old interfaces were not good, to put it mildly. Think what it was like ordering a cab 15 years ago? Any app that made that experience better became a way to own the user. And in the same way, OpenFin realised it could put very timely information in front of very pressurised users in the financial world, and thus amp-up their productivity by several degrees. It seems so simple, really.

But that simplicity has, today, led OpenFin to secure a $35 million Series D funding round, taking it to $82 million raised to date. This round was led by Bank of America with significant participation from Pivot Investment Partners and ING Ventures. Additional investors in the round include CME Ventures, CTC Venture Capital, SC Ventures and Tribeca Early Stage Partners.

OpenFin’s web-based OS has managed to carve out a place in the financial services market as an interface for applications, and, the company says, it’s now used by more than 3,800 banks, wealth, and asset management firms in 60+ countries.

Admittedly, one of its main competitors is Island, which bills itself as a secure web browser for the enterprise. To date, that company has raised $285 million from the likes of Insight Partners and Sequoia Capital, among others.

However, it’s clear there’s more than just a battleground of browsers at stake here.

The so-called “toggle tax,” where users switch from one app to another hundreds of times a day, is well known to cost an inordinate amount of time, and time, especially in the financial world, is money.

Over an interview, Mazy Dar, CEO of OpenFin told me: “We realised that the problem that we were solving wasn’t a financial problem specifically. It’s really an enterprise problem… where you have desktops that are locked down.”

“Think of this as Spotlight Search on steroids. A single search interface that can plug into all of the apps that you’re using. So with one search you can search across all the apps and get really rich results that can then drive workflow,” he added.

Other major OpenFin investors include Barclays, CME Ventures, DRW Venture Capital, HSBC, ING Ventures, J.P. Morgan, SC Ventures and Wells Fargo Strategic Capital. VC investors include Bain Capital Ventures and NYCA Partners.

The number of financial institutions using OpenFin is claimed by the company to have reached 3,800, across 60+ countries, with the latest deal being with the London Stock Exchange. The company has also expanded its footprint to the US government sector through a strategic partnership and investment from In-Q-Tel (the CIA’s investment arm).