[Tex/LaTex] Which package should I use for doing a connecting homomorphism diagram like this in latex

Question

which package should I use for doing a diagram like this in latex:

Answer 1

Using xy-pic package for Commutative Homomorphism diagrams. your diagram was made using xy-pic as suggested by Qrrbrbirlbel in his comment

code for diagram

\documentclass[12pt,border=5pt]{standalone}
\usepackage[all]{xy}
\begin{document}
\xymatrix{
& H^{k+1}(M) \ar[r]^<<<<<<<<<<<{i^*} & \cdots \\
& H^k(M) \ar[r]^>>>>>{i^*} 
& H^k(U) \oplus H^k(V) \ar[r]^>>>>>{j^*} 
& H^k(U \cap V) \ar `[ul] `[l] `[lllu] |{d^*} `[l] [rlllu] \\
&  *{}  & \cdots \ar[r]^<<<<<<<<<<{j^*} 
& H^{k-1}(U \cap V) \ar `[ul] `[l] `[lllu] |{d^*} `[l] [rlllu] }
\end{document}

Output: