BOSL2 library for OpenSCAD
Hacker ApprovedRanked 3 of 4 code-based CAD libraries by recommenders
Extends OpenSCAD with chamfers, fillets, rounding and attachment operations, saving much manual work. Caveat: an extra set of functions to remember, and can be slow with many fillets.
Extends OpenSCAD with chamfers, fillets, rounding and attachment operations, saving much manual work. Caveat: an extra set of functions to remember, and can be slow with many fillets.
25 people gave an opinion
- recommend it
- 22
- criticize it
- 3
- approval share
- 88%
Recommended in 8 of 13 months
- November 2025: recommended
- December 2025: recommended
- January 2026: recommended
- February 2026: recommended
- March 2026: recommended
- April 2026: recommended
- May 2026: recommended
- June 2026: not recommended
- July 2026: not recommended
- August 2026: not recommended
- September 2026: not recommended
- October 2026: recommended
- November 2026: not recommended (month in progress)
Why it carries the badge
- 22 people recommend itNeeds 10 or more, met.
- 7.3 recommenders for every criticNeeds 2 to 1 or better, met.
- Recommended in 8 of 13 monthsNeeds 4 or more, met.
The same three rules apply to every product, and the badge can’t be bought. How the badge works
What people say about it
The reasons people give, with the number of comments that give each one. Open a reason to read what they said.
Why people recommend it
Each mark is one comment
Easy chamfers, fillets and rounding
“alleviates most issues I've run into with OpenScad for chamfers and the like, but it is an extra set of functions you need to remember sadly”
Comment from 31 Mar 2026 in “Open source CAD in the browser (Solvespace)” “BOSL2 is a great library to use with Openscad. It provides a bunch of primitives shapes functions with chamfer/rounding parameters.”
Comment from 28 Jan 2026 in “Parametric CAD in Rust” “adds proper filleting, rounding, and attachment operations that vanilla OpenSCAD lacks”
Comment from 21 Dec 2025 in “OpenSCAD is kinda neat” - Comment from 21 Dec 2025 in “OpenSCAD is kinda neat”
- Comment from 19 Oct 2026 in “RepRapMicron”
Powerful; essential for OpenSCAD users
“it turnes an already very powerful tool into something insane”
Comment from 7 Jan 2026 in “I wanted a camera that doesn't exist – so I built it” “BOSL2 is SO nice and powerful, can also highly recommend it!”
Comment from 20 Dec 2025 in “OpenSCAD is kinda neat” “I'd recommend people to use the BOSL2 library for OpenSCAD”
Comment from 10 Oct 2026 in “OpenSCAD the Programmers Solid 3D CAD Modeller” - Comment from 28 Jan 2026 in “3D-Printed Mathematical Lampshades”
- Comment from 21 Dec 2025 in “OpenSCAD is kinda neat”
- Comment from 23 Jan 2026 in “A Year of 3D Printing”
Attachment points and anchoring
“BOSL2 allows attaching when you define attachment points or something with attachment points defined for you”
Comment from 20 Dec 2025 in “OpenSCAD is kinda neat” “Anchoring is a huge improvement, which does eliminate a lot of that work.”
Comment from 24 Nov 2025 in “µcad: New open source programming language that can generate 2D sketches and 3D” “the attachments with BOSL2 are really great”
Comment from 28 Jan 2026 in “Parametric CAD in Rust” Covers extra features you'd otherwise build
“I also have to recommend the BOSL2 library which means you don't have to implement all of those one million features”
Comment from 20 Dec 2025 in “OpenSCAD is kinda neat” “most of my additional feature needs are covered by the BOSL2 library”
Comment from 19 Nov 2025 in “Blender 5.0”
What people warn about
Each mark is one comment
Extra functions to remember
“alleviates most issues I've run into with OpenScad for chamfers and the like, but it is an extra set of functions you need to remember sadly”
Comment from 31 Mar 2026 in “Open source CAD in the browser (Solvespace)” Slow with many fillets
“It's also extremely slow: it implements chamfers and fillets using morpho, and if you have a large number of fillets, the morpho algorithms”
Comment from 31 Mar 2026 in “Open source CAD in the browser (Solvespace)” “It's also extremely slow: it implements chamfers and fillets using morpho, and if you have a large number of fillets”
Comment from 31 Mar 2026 in “Open source CAD in the browser (Solvespace)”
Other code-based CAD libraries people recommend
The three most recommended other code-based CAD libraries, with the same counts for each, so you can compare like for like. The tick on each bar marks the 2 to 1 line the badge needs.
See all 4 code-based CAD libraries, rankedWhat people said
27 of the 29 comments that mention it, newest first. Each links to the original comment.
“makes cubes with round edges so much easier”
“The BOSL2 library makes it easy”
“BOSL2 library combined with LLMs really make me fly with my creations”
“I'd recommend people to use the BOSL2 library for OpenSCAD”
“I've one shotted a light saber hilt with threaded parts and it worked flawlessly.”
“I learned about BOSL(2) and wrote even more”
“It's also extremely slow: it implements chamfers and fillets using morpho, and if you have a large number of fillets, the morpho algorithms”
“It's also extremely slow: it implements chamfers and fillets using morpho, and if you have a large number of fillets”
“alleviates most issues I've run into with OpenScad for chamfers and the like, but it is an extra set of functions you need to remember sadly”
“takes away enough of them to make a rewarding experience”
“What has really made much better at OpenSCAD is ClaudeCode or Antigravity in VSCode, with BSOL2 library”
“I wouldn't really consider using OpenSCAD without it”
“the attachments with BOSL2 are really great”
“BOSL2 is a great library to use with Openscad. It provides a bunch of primitives shapes functions with chamfer/rounding parameters.”
“if you combine it with BOSL2 you can do miracles”
“it turnes an already very powerful tool into something insane”
“adds proper filleting, rounding, and attachment operations that vanilla OpenSCAD lacks”
“BOLS2 did everything that I could do but better.”
“It can do rounding or chamfering very easily.”
“BOSL2 is SO nice and powerful, can also highly recommend it!”
“but also means you can't use BOSL2”
“BOSL2 allows attaching when you define attachment points or something with attachment points defined for you”
“it had some reasonable options for some gear and rack-and-pinion modeling that I needed to do”
“Libraries like BOSL2 provide a good set of core ideas and preferences that help set you on a good path.”
“I also have to recommend the BOSL2 library which means you don't have to implement all of those one million features”
“Anchoring is a huge improvement, which does eliminate a lot of that work.”
“most of my additional feature needs are covered by the BOSL2 library”
Counts come from 1,795,640 Hacker News comments, November 2025 to November 2026. How we count. Report a mistake.