SLiM

Evolutionary Simulation Framework

About SLiM

SLiM is a free, open-source evolutionary simulation framework that combines a powerful engine for population genetic simulations with the capability of modeling arbitrarily complex evolutionary scenarios. It uses a custom scripting language called Eidos that provides interactive control over virtually every aspect of a simulation.

SLiM is optimized for modeling entire chromosomes in large populations. It is released under the GNU General Public License version 3.

Version 5.1

Downloads

macOS Installer (.pkg) Source Code (.zip) SLiM Manual (PDF) Eidos Manual (PDF) Reference Sheets (ZIP) SLiM Recipes (ZIP)

SLiMgui

With the SLiMgui graphical modeling environment (compatible with macOS, Linux, and Windows), you can visualize your simulation as it runs and examine its parameters in real-time, allowing for much easier simulation development.

SLiMgui screenshot showing a CRISPR/Cas9 gene drive simulation with population structure, genetic variation, and individual fitness visualization

Community

GitHub Repository

Source code, issue tracking, and contributions.

github.com/MesserLab/SLiM →

SLiM-Extras

Community-contributed recipes, scripts, and examples.

github.com/MesserLab/SLiM-Extras →

slim-announce

Low-volume announcements list (read-only).

Subscribe →

slim-discuss

Community discussion and user questions.

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More

Workshops

Upcoming & past workshops, exercise materials, and how to host one.

Videos

Introductory talks, power-user tutorials, and technical deep dives.

News

Complete release history from SLiM 2.0 through 5.1.

Icon & Branding

SLiM icon, QR code, and typeface assets for download.

Citation

If you use SLiM in your research, please cite the appropriate paper(s):

SLiM 5: Eco-evolutionary simulations across multiple chromosomes and full genomes. BC Haller, PL Ralph, PW Messer. Molecular Biology and Evolution 43(1), 2025. DOI →
SLiM 4: Multispecies eco-evolutionary modeling. BC Haller, PW Messer. The American Naturalist 201(5), E127–E139, 2023. DOI →
SLiM 3: Forward genetic simulations beyond the Wright–Fisher model. BC Haller, PW Messer. Molecular Biology and Evolution 36(3), 632–637, 2019. DOI →
Tree-sequence recording in SLiM opens new horizons for forward-time simulation of whole genomes. BC Haller, J Galloway, J Kelleher, PW Messer, PL Ralph. Molecular Ecology Resources 19(2), 552–566, 2019. DOI →
Evolutionary modeling in SLiM 3 for beginners. BC Haller, PW Messer. Molecular Biology and Evolution 36(5), 1101–1109, 2019. DOI →
SLiM 2: Flexible, interactive forward genetic simulations. BC Haller, PW Messer. Molecular Biology and Evolution 34(1), 230–240, 2017. DOI →
SLiM: Simulating evolution with selection and linkage. PW Messer. Genetics 194(4), 1037–1039, 2013. DOI →