Mimalloc

mimalloc (pronounced "me-malloc") is a free and open-source compact general-purpose memory allocator developed by Microsoft^[2] with focus on performance characteristics. The library is about 11000 lines of code and works as a drop-in replacement for malloc of the C standard library^[3] and requires no additional code changes.^[4] mimalloc was initially developed for the run-time systems of the Lean and Koka languages. Notable design aspects include free list sharding, eager page reset, and first-class heaps. It can co-exist with other memory allocators linked to the same program. mimalloc is available on Windows, Mac OS X, Linux and *BSD.^[5] The source code is licensed under MIT License and available on GitHub.^[6]

mimalloc

Original author(s)	Daan Leijen / Microsoft Research
Developer(s)	Microsoft
Initial release	July 2019; 5 years ago (2019-07)
Stable release	3.0.3[1]  / 18 May 2025
Repository	github.com/microsoft/mimalloc
Written in	C
Operating system	Windows, FreeBSD, NetBSD, DragonFly BSD, macOS, Linux
Type	Software library
License	MIT License
Website	microsoft.github.io/mimalloc/

See also

• Free and open-source software portal

• C dynamic memory allocation – Dynamic memory management in the C programming language
• Manual memory management – Computer memory management methodology
• Dynamic memory allocation – Computer memory management methodologyPages displaying short descriptions of redirect targets
• Hoard memory allocator – Memory allocator