Markus Holler is a German game music composer known for his collaborations with Merregnon Studios. Holler took recorder lessons at primary school and subsequently learned the piano for three years. Influenced by his musical father, Holler enjoyed the music of orchestral film composers and Celtic artists while growing. Based on these influences and classic game composers, he started teaching himself how to compose in the late 1980s using the Commodore 64 sound chip. He later started MOD tracking using the Amiga and MIDI sequencing on the Atari.

Between 1994 and 2003, Holler worked with demoscene developers Virtual Dimension creating music and sound effects for their games such as Walls and video presentations about classic gaming.  Between this work, he scored the RPG The Holy Trinity and produced music for the television program Blickpunkt Ingelheim. In 2000, his music was popularly exposed with Thomas Boecker's fantasy trilogy Merregnon. Holler's compositions for the first volume blended worldly influences, beautiful melodies, and rich orchestration. Soon after, he contributed to the fanmade Remix 64 tribute albums.

Holler was asked to recreate the expressive musicality of the Merregnon trilogy with his score for the German MMORPG Tales of Tamar. On behalf of Merregnon Studios, Holler subsequently engaged in high-profile game collaborations with Fabian Del Priore on Hotel Giant, Chicago 1930, and Cold Zero: No Mercy as an additional music composer. He showed further versatility with his orchestral music on Vandell: Knight of the Tortured Souls and Glory of the Roman Empire. In 2003, Holler attended the Leipzig Symphonic Game Music Concert featuring some of his music from Merregnon II.

In recent years, Holler has produced additional music for a small number of game scores. Nevertheless, he achieved acclaim with his epic compositions for S.T.A.L.K.E.R. - Shadow of Chernobyl that were performed by the FILMharmonic Orchestra Prague. A medley from this title was performed in concert at Leipzig before the much-delayed game's release. He has also achieved acclaim for his Death Mask arrangement performed by instrumentalists on Immortal 3. Away from game scoring, Holler has worked on audio plays, trailer music, and the new fantasy Internet station Radio Rivendall.