Roadmap
This list represents is a rough list of ideas that some of the core developers have discussed over the years as the likely next directions for GnuCash. That sentence is mightily-qualified as it should be; this list should not be interpreted as a promise or even really "official"... while it's a good guess as to what one group of people would like to do, projects like GnuCash are the results of a wide group of contributors, and they ultimately decide what road GnuCash travels.
Contents
Register rewrite
The current register is optimized for visual similarity to a "checkbook register" at the expense of simplicity and maintainability. It's also written at too low a level, in large part because it was written early in Gtk+-2's lifecycle when the appropriate layout widgets weren't available.
Eliminate deprecated widgets and libraries
Gnucash still uses several gtk and gnome widgets that have been marked as deprecated. An effort is underway to eliminate most of these in the 2.2 release. There is one deprecated widget that can't be removed in that time frame because gtk is missing the equivalent functionality.
Several of the Gnome libraries upon which Gnucash now depends (libart_lgpl, libbonobo, libbonoboui, libglade, libgnome, libgnomecanvas, libgnomeprint, libgnomeprintui, libgnomeui, and libgnomevfs) have been deprecated for several years now, and will be removed from Gnome3, scheduled for release in January 2011. While most distributions will continue to support Gnome 2 for awhile, we'll need to migrate to the newer replacements soon.
In order to continue to provide backward compatbility, this may mean that we have to emulate Gtk+ and have two development branches, one for Gnome 2 and one for Gnome 3.
Database and QOF
Now that we have the DBI backend supporting not just Sqlite3 but Postgresql and MySql as well, we want to move away from a "load everything into memory at the beginning" model to "load only what you need, and take out a backend write lock only on what you're editing" model to allow multiple simultaneous access, to speed up loading large datasets, better data integrity protection, and all of the other benefits provided by a good database.
The current "Query Object Framework" that Gnucash uses rather gets in the way, because while it handles queries acceptably well, it doesn't offer any of the other services that a proper database does.
Generic importer
TSV/CSV importing "simply" needs a dialog to do column-semantics mapping.
Scheme minimization
There are some parts of GnuCash that make a round-trip into scheme code for no really good reason.
"Invert" reports
Right now reports are scheme scripts that programatically generate HTML. They should instead -- at least for HTML generation -- be HTML templates that embed scheme fragments to control looping and variable output.
Remove module system
The current module system confuses runtime-loaded modules with shared libraries. As well, it is (arguably) at the wrong level of granularity in places, leading to too many modules.
Better MVC split
There is too much application logic in the user-interface handling code. It should move out into some not-yet-fully-defined model layer.