Fortune confirmed Anthony’s passing in Birmingham, Ala. with several of his friends and business associates, who also shed more light on an unusual career that rarely included the primary objective of most venture capitalists: Making money.

Anthony was founder and managing partner of 21Ventures, which billed itself as investing “in clean technologies and entrepreneurs focused on solving the challenges of the 21st Century.”

But 21Ventures never raised a traditional venture capital fund. Instead, Anthony would identify investment opportunities and then pitch them to a small stable of high-net-worth individuals and family offices. Kind of like a “fundless sponsor” model, except that Anthony did not collect management fees. Instead, his only compensation was in the form of carried interest – meaning that he only earned income if the investment was a success, even though most 21Ventures deals were in startups that, even in best-case scenarios, wouldn’t generate a return for years.

And, as we all know, cleantech hasn’t had too many best-case scenarios. Many 21Ventures investments failed, although there are still around a dozen remaining portfolio companies. Later on, he would receive occasional finder’s fees from investors, but not nearly at industry standards.

Among those who leaned heavily on Anthony was David Gelbaum, the mathematician and philanthropist who is believed to have invested around $500 million of his own money in cleantech companies. Gelbaum’s deals were done via a family vehicle called Quercus Trust, which is listed as the lead investor on the vast majority of 21Ventures deals. By 2009, Gelbaum seemed to be having some liquidity troubles. He canceled his annual $20 million-plus gift to the ACLU and, at around the same time, 21Ventures significantly slowed down its investment pace. In fact, one source said that Anthony hadn’t done a new deal in the past two years.

“Gelbaum is a mathematician and a trader, not a venture capitalist,” said one source familiar with the situation. “But he was motivated to invest in cleantech due to his political ideologies, so he basically outsourced a lot of the venture capital to Anthony.”

UPDATE: David Gelbaum sent an email in response to this post. Here it is, in part:

I invested in cleantech to make money, not because of my political ideology. Needless to say, I didn’t make any money. On the contrary, I wiped out my family’s liquidity. Most of my money was not invested in companies recommended by David Anthony. And my biggest losses were not in 21Ventures companies. I think the investments recommended by David Anthony have done better than my other investments, on average. He put good managers in place and made investments subject to milestones. The failure rate on his companies is not too bad, given the traditional failure rate for venture capital and given that the investments were made just before the Great Recession. I think that the companies that have survived have good prospects.

Finally, David Anthony DID want to make money. He charged me an annual fee for managing the portfolio, as he should have, because he had a family to support. He was devoted to his family and worked very hard for them. He was also devoted to his friends.

As of last week, the 21Ventures website listed several employees who no longer seemed to actually work with the organization. The listed phone number rang endlessly without being picked up by a receptionist or voicemail, and the only staffer I could find – principal Dileep Agnihotri, who now works at two portfolio companies – said that he was not yet sure as to who would manage out the remaining portfolio.

As of this morning, the website content has been removed in favor of a sparse landing page.

To be clear, there is no evidence that Anthony committed suicide due to anything related to 21Ventures. In fact, he recently had experienced some family trauma that offers a much more likely explanation. But in passing we remember, particularly someone who mostly flew under the radar during his too-short life.

Anthony leaves behind a wife and young son. A memorial service is expected to occur in early May.