Why we’re not going to support a multimillion dollar company

OSM Buildings
4 min readAug 25, 2020


(Image © Cesium)

We’ve known Cesium since we started OSM Buildings all the way back in 2012. Cesium likewise have been aware of us since the beginning — we grew up together as colleagues in a common market. They got the 3D globe, we got the OSM data. They got 3D tiles, we got the nice buildings.

This all worked fine until one day in June 2020 when we received notice of OpenStreetMap Foundation’s (OSMF) decision to grant Cesium the trademark “Cesium OSM Buildings”.

This was a surprising move, to say the least. Our OSM Buildings project has served the community for a much longer period of time and is well known to the OSMF. Granting a trademark to a commercial service that includes our project name — letter by letter, exactly copying character cases — should have at least raised some questions.

Understandably, we needed to know more and so we reached out to OSMF immediately, asking to postpone the decision process until we had received clarification.

At this point we discovered that “discussions were ongoing” but were taking place on mailing lists that we barely knew about. These discussions were happening in public (which we applaud) but not addressing us. We were surprised to read that we had never requested any trademark protection ourselves. Surprised because we wondered why trademark protection would be needed for a community project?

To be on the safe side, we filed the protection request anyway. Pretty quickly, we got a response, the only reply that OSMF officially made to us. They stated that we would not require a trademark. Great news. Furthermore they made clear that they are not an arbitration board and that we would need to take care of any legal issues ourselves.

This makes some sense. OSMF is not a court. “OSM Buildings” can be used as a common term. How did this become an issue then?

OSM Buildings is not only a free and open source 3D map viewer, it provides a data service that we offer for a fee to commercial users. This helps us cover the cost of operations, staff, our small office and it contributes towards a fraction of the thousands of hours of personal time that are put into this project.

By exactly copying our name, with all of its given popularity, it could easily be argued that Cesium is now making profit from all of that time, dedication and work.

There could have been “Cesium Buildings”, “OSM Cesium Buildings”, “Cesium OpenStreetMap Buildings”, “OSM on Cesium” … it’s not especially difficult to think up variations. Yet it was abundantly clear to us that this name has been chosen with intent.

Still, common words. How is this an issue?

It becomes a serious issue when we think of our old friend, the search engine. If you enter “OSM Buildings” into Google, you’ll find both OSM Buildings and Cesium’s products from now on. Cesium still rank far down but their marketing machine is in full effect.

We also have to consider our community organisation: the OpenStreetMap Foundation. The OSMF could at the very least approach both parties and encourage a settlement, but disappointingly there has been no direct communication. No acceptance or denial. All information has had to be sourced third hand.

Today we saw this press release via OSMF welcoming Cesium as a Silver Member to their party. And we realised:

Each day we keep OSM Buildings running, we support a multimillion dollar competitor.