About us

Mobilism is an initiative of PPK, Krijn Hoetmer, and Stephen Hay. They combine deep knowledge of the mobile web with the necessary organisational skills.

PPK and Stephen speak at nearly every Mobilism conference or workshop. In general Stephen focuses more on the CSS and design side of things, while PPK handles general information and JavaScript. Krijn does not speak. He does an amazing amount of work outside the public eye, though.


Peter-Paul Koch is a mobile platform strategist, consultant, and trainer in Amsterdam, the Netherlands. He specialises in HTML, CSS, JavaScript, and browser compatibility. He has won international renown with his browser compatibility research.

In 2009 he shifted from traditional desktop browsers and sites to the mobile Web, and he never looked back. He discovered that mobile devices and browsers are in even more need of description than their desktop counterparts, and set himself to the task.

On the Web he is universally known as ppk.

Krijn Hoetmer

Krijn is a freelance web developer, who likes to stay in the background a bit. While doing so he's an active volunteer within Fronteers, where he handles the member administration and helps organizing the annual conference, monthly meetups and workshops.

In his other spare time he can be found in his second hand clothes shop, messing around with some IRC logs, playing badminton, trying to perfectly indent HTML with his own crappy CMS or eating salads. He also isn't used to writing about himself in third person.

Stephen Hay

Stephen has been designing and developing for the web since 1995. He was formerly Creative Director of Cinnamon Interactive, one of the first web design and development firms to successfully combine professional visual design with open web standards and accessibility best practices back when table layout was the norm. He now independently consults with clients on design, multi-platform strategy and accessibility through his new company, Zero Interface.

Stephen has written for A List Apart, NaarVoren and ChangeThis. Aside from his client work, he speaks and writes on the subjects of CSS3 layout, (web) design and accessibility. He sporadically publishes his thoughts at the-haystack.com.