This is a disc image of the 0.52 Press Version of Half-Life 1. It is often referred to as the "alpha" version of Half-Life 1.

The source disc of this archive was one of several discs that Valve sent out to gaming magazines and journalists back in September of 1997. An owner of one of these alpha discs released an image of his disc copy on Reddit in 2013.

In this Half-Life Alpha (version 0.52) you will find 21 maps from several different chapters, gameplay videos, and also 15 .demo files, that were recorded by Valve.

A tutorial on how to set up the worldcraft  so you can create your maps for this version.