Don Hosek is a writer and computer programmer living outside Chicago. He began using TEX in 1986 when he discovered it had been recently installed on the IBM mainframe at the University of Illinois at Chicago. By virtue of being one of the first users of TEX at UIC, he became the local expert. While still an undergraduate, he became the Device Drivers Editor for TUGboat and published the e-Magazine TEXMAG. He wrote DVIview, a previewer for TeX and LATEX output that ran on VM/CMS systems and the VM/CMS change file for the MFT program (finding a bug in the program in the process earning him one of the coveted Knuth checks). He later maintained the public domain change files for VAX/VMS and the ymir TEX archive, a predecessor to CTAN.

In the late 1980s and 1990s he taught LATEX classes for the TEX Users Group (and one Metafont class) and this experience is the core of the work behind The Preppy Lion books. In the late 1990s he edited Serif: The Magazine of Type & Typographywhich was typeset using TEX and featured writing by typographic notables including Robert Bringhurst, Allen Haley, Jeffrey Keedy, Jean-François Porchez and Erik von Blokland.

He is currently working on finl, a program meant to be a successor to LATEX, based on remedying the pain points around LATEX. This is a ground-up reimplementation of LATEX, discarding the TEX macro language in favor of a more flexibly and intuitive programming model.