It began as a website. In 1999, Walter Hoeijmakers and Jurgen van den Brand were running a blog about stoner rock, the desert-fuzz heavy music that bands like Kyuss and Fu Manchu had grown out of the American Southwest. The blog was called Roadburn. They started promoting concerts under the same name, scattered across Dutch cities, and in December 2001 the founders pulled in a coup. Masters of Reality played Tilburg's 013 venue with Josh Homme and Nick Oliveri sitting in, because Homme had lived in Amsterdam during the gap between Kyuss and Queens of the Stone Age and considered Hoeijmakers a friend. The show was streamed live and it traveled the internet. Hoeijmakers still credits Homme for the moment Roadburn became a festival rather than a fan site.

Since 2005 Roadburn has lived inside Tilburg's 013 concert hall, with overflow rooms at Het Patronaat and a smaller venue called V39 added as needed. The festival became multi-day in 2006, expanded to four days in 2008, and quickly began selling out within an hour. The 013 holds a couple of thousand people in its main room. Roadburn caps the whole festival at under 10,000 across all venues, which is part of why it won the 2023 European Festival Award for Best Small Festival. Smallness is the point. The audience and the bands share the same beer gardens and tobacco-stained back rooms, and a Roadburn lanyard is less an admission ticket than a guild membership.

Every year, Roadburn invites a guest curator. Sunn O))) did it in 2011. Voivod in 2012. Tom G Warrior of Celtic Frost and Triptykon shaped Friday 2010 around death and ritual. Mikael Akerfeldt of Opeth chose the 2014 lineup. Jacob Bannon of Converge made 2018 a Converge retrospective and played the band's albums You Fail Me and The Dusk in Us on separate nights in full. The curator model means each Roadburn carries an aesthetic signature, but it also means the festival becomes a creative commission. Sleep returned in 2019 and turned down a far more lucrative Coachella slot to come back. Bands have premiered collaborations at Roadburn that later became studio albums: Emma Ruth Rundle and Thou's May Our Chambers Be Full, Full of Hell and Nothing's When No Birds Sing, Drowse and Ragana's Ash Souvenir.

The genres on a Roadburn poster do not fit on a poster. Doom metal sits beside Irish folk, then dark ambient, then a Konnakol-influenced classical piece, then drone, then noise rap. The 2024 headliners included The Jesus and Mary Chain, the Irish folk band Lankum, the rappers Clipping, and Khanate, an extreme noise project performing for the first time in nineteen years. The Luxembourg paper Woxx noted what longtime attendees already knew: Roadburn books more women, more queer artists, and more non-Western performers than other metal festivals. Hoeijmakers' explanation is unfussy. Forward-thinking music attracts forward-thinking people. The festival does not advertise its politics. It just programs them.

For one weekend each April, the Old Dutch wool city becomes the unlikely capital of adventurous heavy music. The 013's neon glows over the canal-side Spoorzone neighborhood. Distorted bass shakes the cafe windows on Veemarktstraat. Tickets to next year's festival go on sale, in the foyer, on the final night, and a queue forms before the last band has finished. Then everyone disperses back to twenty time zones, and Walter Hoeijmakers sits down with his bookers Becky Laverty and Joel Heijda and his business director Mijndert Rodolf to begin the cycle again. The motto stays the same. Redefining heaviness.