XILS-Lab is a French software synthesizer company founded in 2008 by Xavier Oudin, based in Grenoble in the French Alps. Prior to starting XILS-Lab, Oudin spent seven years at Digigram working on speech processing and noise reduction, followed by six years at Arturia where he helped develop landmark virtual instruments including the Minimoog V, CS-80V, ARP 2600V, and Prophet V. He co-founded Eiosis in 2005 to develop effects plug-ins before establishing XILS-Lab to pursue his own synthesizer designs.

The company specializes in detailed software recreations of rare and iconic hardware synthesizers. Their flagship products include the XILS 3, modeled on the EMS VCS3 (the world's first integrated portable synthesizer); the PolyKB, based on the exceptionally rare RSF PolyKobol 2; the PolyM, inspired by the Polymoog; and The Eighty, based on the Yamaha CS-80. The KaoX takes a different approach, combining FM synthesis with analog-style oscillators, filters, and chaotic algorithms. Beyond synthesizers, XILS-Lab produces a line of vocoders — the XILS 201, XILS V+, and XILS 5000 — as well as effects including the LX 122 rotary speaker, Ring'X ring modulator, and Chor'X chorus.

XILS-Lab's instruments are available as VST, VST3, Audio Units, and AAX plug-ins for macOS and Windows. The company has built a reputation among electronic musicians and sound designers for the analog authenticity of its synthesis engines, reflecting Oudin's deep background in both signal processing research and virtual analog instrument development.

XILS-Lab has 9 products cataloged on Equipboard, including Synth Plugins, Vocoder Plugins, and Drum Machine. Their gear is featured by 5 artists, with the strongest followings in Electronic and Hip Hop. Notable users include Noah "40" Shebib, Tycho, and Lustmord.