I have checked it out, it bears very little resemblance to 4e. The take on the Warlord as an archetype was especially disappointing.
The degree of success dice mechanic is an excellent effort at getting more out of the d20, though.
13th Age is closer in spirit, but it returns to D&D's traditional varied mechanical resource schemes, and uses a blunt-force recharge schedule to balance them.
ORCUS seems like a real labour-of-love effort to clone 4e, and it uses almost every SRD out there to try to piece it back together.
But, you just can't clone 4e the way PF1 was a clone of 3.5, the GSL is too great of an impediment. Under the GSL there could have been continuing support, but, you do need to get WotC's permission under it, and, last I heard, they'd stopped responding to anything regarding the GSL.
WotC has made some vague statement about maybe releasing older editions to Creative Commons. Unless that actually happens, 4e will remain essentially contraband D&D.
@Tony Vargas no hate genuinely curious, what are your thoughts here and why did they result in you putting the sadface react on my post? if a class has little to no ability in the social or exploration pillars besides the most default options available to everyone should they not be a comparatively superior entity in the combat pillar? (or any combination thereof between their ability in the three pillars)
No worries.

That kind of reasoning seems fine on the surface, it'd be fair, right, if one class wasn't so good at combat, but was great at other important things like, oh, finding & disarming traps, sneaking past monsters, climbing sheer surface and the like - the Exploration pillar, no?
Well, that class was the Thief, in Greyhawk Supplement II (1975) and it sucked. Mainly because it was actually really bad those things, in addition to being really bad at combat. But, even at higher levels, where it achieved competence, the net effect was that a Thief player would sneak about ahead of the party, doing his thing with the DM, while everyone else waited, then if it found a monster that couldn't be avoided, either die if it spotted him, or hide on the sidelines and try to backstab (another rule so vague whether you'd ever use it was entirely up to the DM).
What became like, the poster boy for that kind of balance, tho, was the cyberpunk netrunner, who would just go on a VR adventure by itself, eating up solo table time, then be useless when the rest of the party did anything in the real world.
Another obvious issue is if a campaign leans heavily towards one pillar, the character options that sacrifice that pillar to be good in another become non-viable. And the ones that do the opposite dominate, so even 'balanced' characters good in all pillars become laggards compared to the single-pillar specialists. And, while that might seem like it's easily side-stepped by just, only playing the characters best for the pillar that gets the most play in a campaign, well, while some campaigns are 'balanced' and others all but single-pillar, a campaign can also vary over time, or turn out differently than everyone planned (a wonder of RPGs, really)
RPGs are games, and games should keep most of the players engaged, most of the time.
Characters should be contributing most of the time.