GNUCash is opensource accounting software.

This requires slib, libofx, ORBit2, GConf, libtasn1, gnome-keyring, 
gnome-mime-data, libbonobo, gnome-vfs, libgnomecanvas, libgnome, libbonoboui, 
libgnomeui, libgnomecups, libgnomeprint, libgnomeprintui, gtkhtml, and goffice.

aqbanking is optional, but it's not available at SlackBuilds.org.

Building the deps in the order listed above should give the desired results.
