Founders

Founders are users who have purchased special packages that include platinum (the secondary in-game currency of Warframe) and special forum emblem specific to the package that was purchased. Three packages include special "Prime" equipment. Packages can be upgraded once purchased.

The Founders program can be seen here on the official Warframe website.

If you are a founder, you may have your badge applied to your user page.

Founders Program
There are 4 packages:

Disciple is the lowest level at only $20 USD (€18). It comes with the fewest bonuses.

Hunter is the next tier at $50 USD (€45) and comes with a substantial Platinum bonus. It is also the lowest level to gain a Prime item, Excalibur Prime.

Master is the third tier for $100 USD (€90), and comes with enough plat to purchase all warframes and slots for them. It also includes another Prime Item, Skana Prime. The master is the first package to come with the privilege to view the design council forums and vote on features for the game.

Grand Master for $250 USD (€225) is the final tier and comes with enough platinum to purchase nearly everything in the game that can be bought with platinum. This package also includes all the Prime equipment and any player with this level has his or her name placed in the game as a Solar Landmark.

Platinum
Each of the packages come with platinum. The ratio of dollars to platinum is much better than paying for just platinum.

Badge
Badges are visible in the bottom right corner of the avatar on the forums to indicate the players founder package.

Prime Equipment
Prime Equipment includes an Excalibur Prime, Skana Prime, and Lato Prime. They have slightly adjusted statistics from their non-prime counterparts, and special skins that stand out from the design of the rest of the game.

Beta Keys
Beta keys were given to 3 of the tiers for the player to give to other potential players to participate in the closed beta program.

Design Council
Design Council privileges are given to the top two tiers. This includes the ability to view design council forums (hidden to other players) and vote on designs, features, and names in the game. The staff is significantly more involved in the design council forums. Many announcements about the game are released there before announced to the free community.

Solar Landmark
The Solar Landmark is a descriptor of every mission in the game. It is displayed in a text ticker in the lower right of the info box of planets when the mouse is hovered over any available (i.e. not locked) mission node. The symbol is that of the Grand Master and the text is the user name of a Grand Master. If a player is a Grand Master, the shortcut to the left of the game mode selection button in the form of the Grand Master star symbol, will take the Grand Master to their own Solar Landmark as well as displaying one of the following messages, voiced by the Lotus:
 * "Now the Tenno are stronger by your hand, Grandmaster."
 * "The Lotus is pleased to be in the presence of a Grandmaster."
 * "We are in your debt, Grandmaster. Thank you."
 * "The Tenno have gained great strength thanks to you, Grandmaster."
 * "With your support Grandmaster, the Tenno will rise again."

With 207 missions and every mission having 6-9 Solar Landmarks (as of 5-10-2013), over $388,000 USD has been donated from the Grand Master program alone.

Availability
While no dates have been announced concerning the end-date of the program, it was supposed to end before the game went from closed beta to open beta; however, it was extended. This was partly to allow the new users brought in by the game's Steam release to be able to buy it, but also to give the developers more time to "nail down an incredible follow up offer to the Founders program", according to an administrator.

Upgrading
Once a player has purchased one of the lower three packages, he or she can later upgrade to one of the other higher tiers for the difference of the price. Doing this will earn the difference of the rewards (e.g. going from Disciple to Hunter will earn the user 850 platinum, as well as Excalibur Prime).