Overview: This generator is designed to make a wide variety of dragons, with as much customization as reasonable. You can just choose a type and age and generate, or you can select nonstandard stats and add templates.
These are links to similar pages written by others. If you don't like my dragon generator, try:
Dragon's Lair Dragon Generator - This is a VB executable (designed for Win 95/98/ME/2000). Enter color and age, or let it choose one at random (subject to alignment/CR restrictions, if you add them). Clean, easy to use.
Instant dragon generator - This generator allows you to select a dragon type or CR and get back text. It doesn't do stats – but that's what other generators are for!
Dragon type: The particular race or kind of dragon.
Age category: Groups based on the age (and thus, power) of the dragon. Wyrmling (0-5 years), very young (6-15 years), young (16-25 years), Juvenile (26-50 years), young adult (51-100 years), adult (101-200 years), mature adult (201-400 years), old (401-600 years), very old (601-800 years), ancient (801-1000 years), wyrm (1001-1200 years), great wyrm (1201 years or older). Some sourcebooks use other age categories (e.g. WotC's ELH, Mongoose's Slayer's Guide to Dragons); I may add such a category to the generator, provided it's open content.
Advancement: The number of Hit Dice to advance. This may modify the CR (using the old, inaccurate rules – I'm waiting for an SRD update). You can advance a dragon beyond its normal limit, but the generator will warn you against so doing.
Base stat type: The base (unmodified) stats of the dragon. For example, red dragons have folowing base stats (at all ages): Str 11, Dex 10, Con 11, Int 10, Wis 11, Cha 10. Their racial ability modifiers apply to these, as normal. Choose "standard" to generate a dragon with stats as written; "random" to roll 3d6 for the base stats, and "choose" to enter yoru own base stats. This could be useful for "boss" dragons as well as PC dragons wit elite stats.
Templates: Check whatever templates apply. Illegal or silly combinations can't be selected; there are no celestial half-fiend red dragons, for example, and the celestial half-celestial just sounds silly. I may add more templates as time and the OGL allow.
Open new window: If you want to copy/paste the HTML for the dragon, or just like pop-ups, select this option. The HTML behind the dragons should be pretty clean; I like well-organized code.
Make dragon: Makes the dragon's stats. Choose stat block for a compact format, or MM block for the more verbose style used in monster books.
Legal information is on my OGL page.