Many users look for a "non-steam" download for several reasons:
Original retail copies of Half-Life or the Half-Life 1 Anthology (2005) used a simple disc check or CD key. These versions can be played offline without Steam if extracted correctly, though they are for the original engine rather than the Source port.
Since 2013, Valve granted the Sven Co-op team permission to include all original Half-Life maps and assets for free.
