Valve composer and audio artist Mike Morasky publicly mentioned "HLX" during a GameSoundCon panel, confirming that Valve does use this term internally. However, existing information does not prove that HLX is the latest sequel in the series, Half-Life 3.
Morasky was discussing an open and flexible audio engine. When asked about the number of simultaneously playing sounds and HDR audio optimization, he stated that Deadlock has its own HDR version, adding that "HLX also has its own version." This marks the first time a Valve employee has clearly mentioned "HLX" in public.
David Feise, who was present at the same event, later reacted to these remarks and noted at the end of the panel that Morasky "only said HLX once." This incident further fueled speculation, but it only serves to confirm that HLX is an internal term used by Valve, without determining the specific project it refers to.
HLX first drew attention in 2024 due to data strings found in a Counter-Strike 2 update, with its format believed to be similar to the internal codename "HLVR" for Half-Life: Alyx. However, no corresponding new title has been announced since. HLX could refer to a new Half-Life project or an internal technology, though it might also be a slip of the tongue or a deliberate attempt by developers to stir up discussion. PC Gamer editor Tyler Wilde speculated in 2025 that Valve might be working on a new Half-Life game, but did not assert that it would necessarily be the third mainline installment.