*'MELINDA -BILL'S- GREATNESS'*

BILL AND MELINDA GATES FOUNDATION, believed to be the largest in the world, gave away  more than $41 billion from its inception in 2000 through the end of 2016.

And is now spending $4 billion a year to $5 billion a year a year to combat malaria, poverty and improve education.

''There have been some interesting tip-offs about where they're heading or their perspectives on things,'' said David Callahan, the founder and editor of Inside Philanthropy, a news site about  charitable giving.

While the mood in many parts of the world seems to have darkened, Mr. and Mrs Gates say in their letter that they remain militantly optimistic about global progress.

''The headlines are filled with awful news,'' they write in the letter.

''Every day brings a different story of political divisions, violence and natural disaster. Despite the headlines, we see a world that's getting better.''

They expanded on some of those themes and fielded questions about other topics in the recent interview. It was held at bigC3, a company that oversees many of Mr. Gates independent projects including for-profit investments in clean energy.

Through her own private company, Pivotal Ventures, Ms. Gates has advocated for greater participation of women in STEM fields - science, technology, engineering and mathematics - and other gender equity issues.

Pivotal recently helped fund Aspect Ventures, the largest venture capital firm led by women. Not long ago, she moved Pivotal to its own private office near her husband's.

As one of the founders of the modern tech industry, Mr. Gates is often looked to for technical answers. For instance, while running for president, Mr. Trump floated the idea of asking Mr. Gates to help close ''that internet up in some way'' to curb communications by terrorists online.

But when asked about the growing criticism that big technology companies like Facebook and Twitter have faced over their role in spreading misinformation. Mr. Gates said he hadn't ''seen great solutions,'' though ''I'm hopeful they'll come.''

The whole tech world should look at these criticisms, look at these effects, you know, try to make sure that without giving up what's good about that, that we can reduce some of it,'' he said.

The Honor and Serving of the latest global Operational Research on global philanthropy continues to Part 3.