I have created an opencollective page to raise a small funding for hosting Approach0 web service. If things go well, I can further include AoPS and MathOverflow source as index (I would cover the additional required hardware resource myself). @Sil, I wish your AoPS crawler can be used somewhere in the near future.

@WeiZhong Nice, do you plan to announce it on some related communities? Although I am not sure what is the policy on MSE to self promoting when money are involved...