I'm going to compile a reference list of software meant to be used with D&D. If anyone has additions to this list, please feel free to contribute. I'll update the master list regularly. Virtual Game Tables: Battlegrounds: RPG Edition
Price: $32 for DM License. $16 for Player. Discounts for group purchases. Trial Available.
Pros: Cross-platform; powerful dice roller that doesn't require any scripting; highly customizable Turn Sequencer; supports sound & music; supports any RPG system and even some boardgames and "light" wargames.
Cons: Hard to find a game on the fly; all players must be using same version of software; maps can't be larger than 4000 x 4000 pixels. FantasyGrounds
Price: ~$40 for DM license. ~$24 for Player. Discounts for group purchases. Demo Version available.
Pros: 3D Dice Rolling, Character Sheets & Combat Tracker (customizable with rulesets), Savage Worlds ruleset purchasable, free 4th Edition D&D community ruleset available.
Cons: Windows (DirectX), Self-customization requires XML/LUA proficiency MapTool
Pros: Active Development, Line of Sight tools, Fog of War, Easy to install.
Cons: Hard to find a game on the fly, All players must be using same version of software. OpenRPG
Pros: Game Tree for Organization, Multiple Games per Server, Extensible with custom tools, Most popular, easiest to find a game on the fly with.
Cons: Not Easy for Novice to install. Steep learning curve to use all the features. GameTable
Pro: Fast, Easy, Sufficient if you only need a pure Battlemap
Con: Not many functions, No textures or objects can be placed, Extremely Basic Game Management(DM Tools) DM Genie InitTool
Pros: Integrates well with MapTool
Cons: Dungeon Master's Battle Screen
Cons: DM's Toolkit
Pros: Fast & Easy to use, Active Support
Cons: Not yet finished (Ritual, Item and Feat Creators missing), no Mac-Version (yet) DM's Familiar
Cons: DragonScript DM Tools
(Treasure Generator, Encounter monitor, more to come)
Pros: Easy to use, instant results, output to plain text, platform independent
Cons: Web-based, limited to core books (at the moment), only one tool finished (and it only works up to Paragon). Infrequent updating. Character Creation PCGen
Pros: Cross-platform, active development, broad user-base, open data files, documentation to help add custom content to data files, many 3pp data files included in download, active user groups to ask help from, Open Source (Code under LGPL, Data mostly under OGL)
Cons:Non-intuitive interface, Java based so it runs slower than expected, data from closed content or sources not included need to be manually input by user. Tinwatchman 4e Starting Character Generator
Pros: Cross-platform, simple interface, outputs characters as raw text.
Cons: Only can create first-level characters, web-based. Redblade
Price: Free DM Genie Pathguy's 4e Generator Misc Dice Roller