\[ \boxed { {\it f0} \left ( x \right ) y \left ( x \right ) {\frac {{\rm d}^{2}}{{\rm d}{x}^{2}}}y \left ( x \right ) +{\it f1} \left ( x \right ) \left ( {\frac {\rm d}{{\rm d}x}}y \left ( x \right ) \right ) ^{2}+{\it f2} \left ( x \right ) y \left ( x \right ) {\frac {\rm d}{{\rm d}x}}y \left ( x \right ) +{\it f3} \left ( x \right ) \left ( y \left ( x \right ) \right ) ^{2}=0} \]
Mathematica: cpu = 49.431277 (sec), leaf count = 41 \[ \text {DSolve}\left [\text {f0}(x) y(x) y''(x)+\text {f1}(x) y'(x)^2+\text {f2}(x) y(x) y'(x)+\text {f3}(x) y(x)^2=0,y(x),x\right ] \]
Maple: cpu = 0.530 (sec), leaf count = 83 \[ \left \{ y \left ( x \right ) ={\it ODESolStruc} \left ( {{\rm e}^{\int \!{\it \_b} \left ( {\it \_a} \right ) \,{\rm d}{\it \_a}+{\it \_C1}}},[ \left \{ {\frac {\rm d}{{\rm d}{\it \_a}}}{\it \_b} \left ( {\it \_a} \right ) =-{\frac { \left ( {\it f1} \left ( {\it \_a} \right ) +{\it f0} \left ( {\it \_a} \right ) \right ) \left ( {\it \_b} \left ( {\it \_a} \right ) \right ) ^{2}}{{\it f0} \left ( {\it \_a} \right ) }}-{\frac {{ \it f2} \left ( {\it \_a} \right ) {\it \_b} \left ( {\it \_a} \right ) }{ {\it f0} \left ( {\it \_a} \right ) }}-{\frac {{\it f3} \left ( {\it \_a} \right ) }{{\it f0} \left ( {\it \_a} \right ) }} \right \} , \left \{ { \it \_a}=x,{\it \_b} \left ( {\it \_a} \right ) ={\frac {{\frac {\rm d}{ {\rm d}x}}y \left ( x \right ) }{y \left ( x \right ) }} \right \} , \left \{ x={\it \_a},y \left ( x \right ) ={{\rm e}^{\int \!{\it \_b} \left ( {\it \_a} \right ) \,{\rm d}{\it \_a}+{\it \_C1}}} \right \} ] \right ) \right \} \]