Singularity began as an open-source project in 2015, when a team of researchers at Lawrence Berkeley National Laboratory, led by Gregory Kurtzer, developed the initial version written in the C programming language and released it[8] under the BSD license.

In May 2020 Gregory Kurtzer left Sylabs but retained leadership of the Singularity open source project.

[27][28] In November 2021 the Singularity open source project joined the Linux Foundation[29] and was renamed to Apptainer.

[30] Singularity is able to support natively high-performance interconnects, such as InfiniBand[31] and Intel Omni-Path Architecture (OPA).

[35] Docker containers can be automatically converted to stand-alone singularity files which can then be submitted to HPC resource managers.