Dalaran

Dalaran is robotics visualization that speaks ROS 2 natively. Log topics, LiDAR, camera streams, and transforms, then get synchronized 3D playback and dataframe export. It's built on Rerun's bones, Apache 2.0 all the way down, and it opens existing Rerun recordings without conversion, so you can point it at your current data today.

Install is pip, cargo, or CMake, with a doctor command for the inevitable ROS 2 environment wiring. What it adds over Rerun is the domain layer: joint states, URDF-driven transforms, correct nav2 costmap semantics, things you'd otherwise hand-marshal. It even ships the self-hostable catalog server, the piece Rerun's commercial strategy sits on.

ROS 2 teams who found Rerun's generic time-series model didn't speak robotics are the audience. Foxglove is the proprietary incumbent; RViz is the free classic that never left.

The catch: this is one person maintaining infrastructure that competes with two venture-backed companies, and the README warns that breaking changes are expected between releases. Impressive work with a real bus-factor question attached.