Haiku:

Haiku was originally released as OpenBeOS. This OS uses the Be File System (BFS) that works as a metadata database running on 400 MHz microprocessor, 128 MB of RAM and 700 MB of HDD space.

Haiku OS ({BotMoveToCommons
          en.wikipedia year={subst:CURRENTYEAR}
          month={subst:CURRENTMONTHNAME} day={subst:CURRENTDAY}
          {Information Description={en Screenshot of the Haiku Operating
          System showing the updated GUI interface.})

have found it interesting that Haiku is partially POSIX-complaint and even included the Bash shell — no learning curve.

The only problem that have encountered has been installing new applications. The repositories that Haiku lists in its website are either not responsive or no longer live. Its package manager (Haiku Depot) is missing from R1/Alpha 4.1 — its stable version released four years ago.

Installing BeOS (Haiku):

Note that have only been able to install Haiku on a VDI, not as a sole OS on a HDD or partition using its .ISO image.

Like most operating systems, the installation is handled by a live disk. The process is straight forward. It loads all necessary drivers including the 802.11 adapter and there is barely any configuration needed.

Although Haiku recommends running its nightly builds, have found them buggy especially when running the default web browser — WebPositive, which did not even let me log in to my Google account.