BurnSim 4 is currently in beta. See the Download page for the latest builds. Please email greg@blastzone.org with bug reports or feedback.

Version 4.0.0.9 - released 7/22/2026
Cross-platform release: BurnSim 4 is now available for Windows, Linux, and macOS (previously Windows-only), with a native Windows installer and Linux desktop-entry packaging
Added win-arm64, linux-arm64, and macOS (Apple Silicon) builds
Replaced the graphics engine with SkiaSharp for consistent rendering across platforms
Added an editable data grid to the Test Data tab; decluttered the tab (dropped Molar Mass from the Propellant UI, hid imported-series checkboxes when not in use)
Added a separate Imported Thrust trace, distinct from the calculated one
Added light and dark theme
Fixed the "Use in simulation" checkbox only re-plotting stale data instead of re-simulating
Fixed long thrust tailoff not resolving correctly (thrust coefficient floor issue)
Fixed the burn loop not stopping once thrust had genuinely ended
Added a warning in the Results text when nozzle efficiency is below 75%
Added Print/Report: a one-page PDF motor report, with direct printing support
Added a play/stop button to loop the grain erosion visualizer
Numeric fields are now rounded to 4 decimals when saving .bsx files and the propellant database
Added a per-field unit override to lock Total Impulse to Newton-seconds
Fixed cored Tablet grains simulating identically to BATES grains, fixed the Tablet erosion preview, and fixed a crash simulating a solid (uncored) Tablet grain
Fixed a graph rendering glitch causing runaway padding/overflow at the end of a burn
Made the Grains/Graph panes vertically resizable, added a scrollbar to the grain grid
Moved the motor Notes field to its own tab, alongside Results/Test Data
Fixed simulation results silently going stale when a field was edited mid-run
Fixed several usability gaps when starting a new motor from scratch
Added a per-run activity log to help diagnose bug reports
Fixed the installer defaulting to Program Files (x86)
Added right-click pickers on the throat diameter field (1/64" increments and Loki Research nozzle sizes), working regardless of unit mode