[6] KolibriOS is small sized and fits on a single 3.5" floppy disk; despite this, it features a full graphical user interface, preemptive multitasking, networking capabilities, and many pieces of bundled software.

The name "Kolibri" is the Russian word for hummingbird (Колибри) and symbolizes the operating system's tiny size and fast speed.

[7] Shortly after the start of the KolibriOS project, MenuetOS's developer decided to only focus on the 64-bit version, which unlike its 32-bit counterpart was closed source.

[7] KolibriOS has been developed by a number of contributors from different countries including Russia, Kazakhstan, Ukraine, Belarus, Uzbekistan, Moldova, Estonia, Germany and Belgium.

Due to its small size (most distributions will fit on a single 1.44 MB floppy disk image[9]) and being written in assembly, the OS boots in only a few seconds on various devices.

It has built-in application software (more than 250[7]) such as a word processor, image viewer, music player, and web browser,[5] as well as a code editor with an integrated macro assembler (FASM).

Jesse Smith from DistroWatch Weekly wrote the following review about KolibriOS in 2009:[15] The application menu is broken down into familiar groupings, such as Development, Games, Data Processing, Network and Help.

In 2024, Simon Batt of XDA Developers wrote that KolibriOS is "charming" and that it is "perfect" for giving new life to older PCs.