In 1993, as a graduate student at the University of Illinois, he co-wrote NCSA Mosaic for Windows with fellow student Chris Wilson while working at the National Center for Supercomputing Applications (NCSA). Mittelhauser was part of the original team of 5 programmers of Mosaic which included: Marc Andreessen (Unix version), Eric Bina (Unix version), Aleks Totic (Mac version) and Chris Wilson (Windows version). The MS Windows version which Mittelhauser and Wilson wrote was the first browser with over a million downloads and is often pointed to as the first widely used web browser.
Mittelhauser attended the University of Illinois at Urbana-Champaign where he joined the Alpha Sigma Phi fraternity and graduated with a Bachelor of Science degree in Computer Science in 1992 and a master's degree in 1994.
In May 1994, Mittelhauser left the University of Illinois and was one of the founders of Netscape Communications Corporation.
Mittelhauser is married with two daughters.
- Jon was one of the founders of Netscape Communications Corporation. In addition to various engineering and engineering management positions, he was also the first marketing product manager for Netscape Navigator.
- Mittelhauser opened "The Basin" restaurant in Saratoga with fellow Netscape-er Bill Foss in 1999.
- After Netscape, Mittelhauser was Director of Engineering for Geocast Network Systems, a high profile start-up funded by Mayfield Fund, Kleiner Perkins Caufield & Byers, and Institutional Venture Partners
- Jon lead the software organization at OnLive, Inc. and managed their successful launch in 2010. He left at the end of 2010 as VP of Engineering and joined their Technical Advisory Board so he was free to pursue other ventures.
- Jon was hired as the Vice President of Engineering for Nebula, Inc. on 5/1/2012.
- Jon accepted the position of Chief Executive Officer of CloudBolt Software, a leading provider of next generation IT cloud management solutions, on 12/1/2014.
- Jon is on the board of directors of the national Prevent Cancer Foundation.
- Jon is on the advisory council for the "Bad Beat on Cancer" initiative.
- Mittelhauser has taken possession of a Tesla Roadster from Tesla Motors. It is a battery electric sports car with a 200-mile range. He was among the first owners. His wife was one of the first to be pulled over by the police in one.
- Mittelhauser is a member of the infamous Tiltboys (a group of poker playing buddies whose exploits have been featured in the New York Times, Smithsonian Magazine, etc.) which also includes professional poker players Phil Gordon, Rafe Furst, and Perry Friedman.
- Jon did an AMA on Reddit in 2011 which presented a lot of interesting insights
- While at NCSA, Mittelhauser created the first ever NCAA pool online as a (free) demonstration site for the new web form functionality which the team had added to the various versions of Mosaic.
- Mittelhauser is believed to be the first person to ever have a URL in his email signature.
- Mittelhauser was the first person to ever see an image embedded within a web page. The NCSA team created the original specification for the IMG tag (much to many SGML purists horror) and the presence of Object Linking and Embedding in windows allowed that platform to support the new feature first. Prior to that time, images only existed on the web as files which were displayed in external applications.
- Mittelhauser joined eta chapter of Alpha Sigma Phi at University of Illinois at Urbana-Champaign in 1990.
- "Legacy: A brave new World Wide Web - CNET News". archive.is. Archived from the original on 13 July 2012.
- Henrik Frystyk Nielsen (December 11, 1995). "People who have contributed to the World Wide Web project". w3.org.
- "[IAmA] co-author of the first widely used Web browser, an early owner/evangelist/investor for Tesla Motors, and the guy who ran the launch of OnLive (a Reddit trifecta?) AMAA : IAmA". reddit.
- "Archived copy". Archived from the original on 2011-07-18. Retrieved 2011-01-04.
- "Company at a Glance: Geocast".
- "Nebula Appoints Web Pioneer Jon Mittelhauser Vice President of Engineering - Business Wire". 1 May 2012.
- "Cloud Management and Self-Service IT Software for Enterprises".
- "CloudBolt Hires Web Pioneer Jon Mittelhauser as CEO". PRWeb. 8 December 2014.
- "Board of Directors". Prevent Cancer Foundation.
- "About". Prevent Cancer Foundation.
- "Updates - Tesla Motors".
- "Archived copy". Archived from the original on 2008-09-24. Retrieved 2008-08-15.