# Andreessen (DD-555)

> Marc Andreessen, born July 9, 1971, in Cedar Falls, Iowa, co-created the Mosaic web browser while at the University of Illinois. Mosaic, the first widely used graphical browser, helped popularize the World Wide Web. In 1994 he co-founded Netscape Communications, whose Netscape Navigator dominated the early web. He later co-founded the venture firm Andreessen Horowitz (a16z). The footage, credited to a16z speedrun, shows Andreessen speaking.

- Department: People (also Tech)
- First published: 2025-04-26
- Last updated: 2025-04-26
- Permalink: https://detailenjoyer.com/case/andreessen/
- Author: Marcus Easterling (DetailEnjoyer), The Detail Department

## On the timeline

- **July 9, 1971**: Andreessen born
- **1994**: Netscape founded

Full timeline: https://detailenjoyer.com/timeline/?case=andreessen

## Quick facts

- **DD-555-F01**: July 9, 1971. _(Write-up · Exhibit A (Born))_
- **DD-555-F02**: Graphical browser. _(Write-up · Exhibit B (Mosaic))_

## Write-up

Marc Andreessen co-created Mosaic as a student. It helped make the web mainstream.

1. **Born**: July 9, 1971.
2. **Mosaic**: Graphical browser.
3. **School**: University of Illinois.
4. **Netscape**: Co-founded 1994.
5. **a16z**: Venture firm.

## Related case files

- [Thiel (DD-554)](https://detailenjoyer.com/case/thiel/): I linked another tech investor

## Reel vs. record

- **Note**: None needed.

## Video: Andreessen: Marc Andreessen Co-Created Mosaic as a Student

- Duration: 23.0 s · Published: 2025-04-26
- File: https://detailenjoyer.com/assets/videos/DI6rNVIx_Mg.mp4

### Transcript

Did you know, Marc Andreessen is an American entrepreneur born on July 9th, 1971 in Cedar Falls, Iowa. While studying computer science at the University of Illinois, he co-created Mosaic, the first widely used web browser with a graphical interface which played a pivotal role in popularizing the world wide web. In 1994, he co-founded Netscape Communications, whose browser, Netscape Navigator, became a dominant force in the early internet era. NOW YOU KNOW!

## Questions & answers

**Q: Browser he co-created?**  
A: Illinois. _(Source: Write-up · Exhibit A (Born) · Wikipedia: Marc Andreessen)_

**Q: Netscape founded?**  
A: Navigator. _(Source: Write-up · Exhibit B (Mosaic) · Wikipedia: Marc Andreessen)_

**Q: Birthplace state?**  
A: Cedar Falls. _(Source: Write-up · Exhibit C (School) · Wikipedia: Marc Andreessen)_

**Q: Venture firm?**  
A: a16z. _(Source: Write-up · Exhibit D (Netscape) · Wikipedia: Marc Andreessen)_

**Q: University?**  
A: Student. _(Source: Write-up · Exhibit E (a16z) · Wikipedia: Marc Andreessen)_

## Sources

- [Wikipedia: Marc Andreessen](https://en.wikipedia.org/wiki/Marc_Andreessen)

## Cite this case file

Easterling, Marcus. "Andreessen." The Detail Department (DetailEnjoyer), case file DD-555, last updated Apr 26, 2025. https://detailenjoyer.com/case/andreessen/