OS/2

Background
OS/2 is a series of OS published and developed by both IBM and Microsoft. The first version of the system was launched in December 1987 and newer versions were released until December 2001. After October 1994, the operating system would then be called "OS/2 Warp" due to the addition of several performance and GUI improvements, starting with version 3.0. It was targeted at professional and server computers. IBM discontinued support of the software in December 31, 2006.

1st Logo (December 1987-December 1990)
Logo: Same as the Windows 1.0/2.0 bootscreen at the time, but the Microsoft logo is replaced by the IBM logo, underneath the IBM logo is "Personal Computer", a border is around the text "IBM Operating System/2 Extended Edition 1.0", copyright notice (altered here) is underneath the bottom of the screen.

Technique: None

Music/Sounds: None.

Availability: Ultra rare. Appears on computers with OS/1 1.0-1.3.

2nd Logo (February 1992-August 1994)
Logo: On a black background we see the copyright info of the operating system below. Above there's various boxes with various colored circles with the text "OS/2" inside them wiping from below piece-by-piece. Those boxes then disappear, followed by a bigger version of the logo forming the same way as the previous boxes. The copyright info changes to "Loading, please wait..." a second after the logo is formed.

Technique: Computer animation.

Music/Sounds: None for the original version.

Music/Sounds Variant: For the multimedia version, startup and shutdown sounds were added.
 * Startup: A "baseball charge" sound played by a trumpet.
 * Shutdown: People clapping.

Availability: Extremely rare. Appears on computers with OS/2 2.0-2.1.1.

3rd Logo (October 1994-February 1996)
Logo: On a black background we see a white box. On the top-left corner there's the IBM logo. The OS/2 box from before is seen near the right, rotated about 40 degrees to the left. The text "Times New Roman" is seen below. Below the box there's a copyright notice.

Technique: None.

Music/Sounds:
 * Startup: A low ascending synth note that builds up a sudden orchestra hit.
 * Shutdown: A descending synth.

Availability: Very rare. Only on OS/2 Warp 3 systems.

4th Logo (June 1995-200?)
Logo: On a black background, we see the warped text "Times New Roman WARP" on the center. The IBM logo is on the top right. Below the text is a copyright notice.

Technique: None.

Music/Sounds: TBA.

Availability: Very rare. Seen on OS/2 Warp Connect 3 systems.

Legacy: This looks like a prototype version of the next logo.

5th Logo (September 1996-December 31, 2006)
Logo: On a marble background, we see the warped text "Times New Roman WARP" on the center. There's the IBM logo on the top-right.

Technique: None.

Music/Sounds:
 * Startup: A calm synth theme with chimes.
 * Shutdown: A loud whoosh, followed by the same descending synth from before, finished by some twinkles.

Availability: Rare. It is found on OS/2 Warp 4 systems. Due to being the latest version of the OS and having a longer support, it's more easier to find than the previous ones.