Half-Life: Chronicles - Episode One
A well received single player modification for Half-Life, Half-Life: Chronicles - Episode One was the creation of the now-defunct RadioActive Software team. Created over the course of several months beginning in late 1999, Chronicles was released on November 19, 1999 to warm reviews.
The concepts and overall idea for the mod were by Sam Shahrani, with the actual design of the levels in Episode One being done by Evan Hort. Evan's own level designs, and the implementations of Sam's designs, resulted in a mod that kept the tone and spirit of the original Half-Life while providing fast-paced gameplay and a new weapon.
Chronicles Episode One added an M4 assault rifle; at the time the mod was begun, Gearbox Software had not announced that there would ever be a High Definition Model Pack released, and so the weapon was added. It features an automatic 3 round burst after each pull of the trigger. Any players that have the High Definition Content installed will see two M4 carbines; one is located in the spot that was occupied by the MP5 in the original Half-Life, and functions like the original MP5. Once the player finds the Chronicles M4, it will be located in the third slot, beneath the shotgun.
Chronicles was one of the first modifications to promote the idea of episodic releases of content, which is now gaining popularity in the mainstream gaming industry. Though the second episode of Chronicles was stillborn due to the breakup of the team, the concept behind the episodic release appears to have been sound.
Half-Life: Chronicles - Episode One was featured in the May 2000 edition of PC Gamer as one of the Top 10 Single Player Half-Life modifications at that time, and was included on the attached CD for that issue.