Valve has produced some memorable games over the years, but recently, they've also received plenty of attention for the sequels they haven't released such as "Half Life 3" and "Left 4 Dead 3."

Fans have been waiting to catch glimpses of both titles for years now, and they've yet to receive official word in recent years that all that waiting will pay off.

That both eagerly anticipated sequels can be traced back to Valve has to concern fans waiting for "Left 4 Dead 3," considering how the wait for "Half Life 3" has just continually dragged on.

Many fans waiting for "Half Life 3" have been on standby since late 2007 and it's worth wondering if the same fate may await those still looking for the next game in the "Left 4 Dead" franchise.

For what it's worth, "Left 4 Dead 2" was released later than the last "Half Life" game, so the wait for the former's follow-up has not been as long.

A leak potentially hinting that "Left 4 Dead 3" is indeed in development was also spotted fairly recently, and it emerged courtesy of a tutorial shared by a Valve employee.

One of the images shown in that tutorial featured a folder with the name"left4dead3." The image in question can still be seen over on ValveTime.

Unfortunately, nothing has come of that apparent leak up to this point and confirmation of the sequel is still lacking up to this time.

If nothing else, the success of earlier "Left 4 Dead" titles would seem to give Valve a good reason to release a sequel, but then again, the "Half Life" games were highly successful too, and that franchise is still in limbo.

At this point, fans have likely recognized the parallels that exist between "Half Life 3" and "Left 4 Dead 3," and sadly, the fate of one eagerly anticipated game may be similar to the other.