``An introduction to homological algebra''

by Charles Weibel, published 1994 by Cambridge Univ. Press (450pp.)

Corrections to 1994 hardback edition;
    these were corrected in the 1995 edition

Corrections to 1995 paperback edition

And in case you missed the movie, here's the visual proof of the Snake Lemma!

Thanks for corrections go to:

O.Gabber, R.Thomason, L.Roberts, S.Geller, G.Peschke, R.Vogt, B.Keller, P.Gaucher, G.Vezzosi, S.Myung, I.Ivanov, J.Moller, J.Soto, B.Koeck, A.Pirkovskii, R.Chapman, A.Brooke-Taylor, C.Mazza, G.Cortiñas, L.Hesselholt, V.Costeanu, J.Morales, P.Polo, G.Wiese, Y.Zhang, J.Berrick, M-F Lim, Y.Zhang, A.Heider, Y.Flicker, M.Raggi, C.Wilkerson, P.Reinhard, R.Cheung, J.Burman, K.Schwede, A.Milas, P.Hackney, P.Zheng, A.Lahtinen, B.Williams, J.Lee, C.Aholt, A.Garcia-Raboso, M.Walker, J.Hornbostel, CL Zhong, C.Haesemeyer, T.Keller, P.Hackney, A.Buch, A.Koerschgen, F.Perroni, F.Catanese, J. Polak, H. Nuer, P.Brosnan, Y.Guerboussa, J.Laubacher, T.Chansler, P.Nicodemus, D.Green, J.Avila, I.Coley, R.Anderson, ...