This simulation is a framework with which many ordinary Stagecast simulations can be converted very easily into their modifiable equivalents.

First, the Design stage appears. It is actually named MX Design.. The bottom row of icons are:

- The Perform/Design switch. Click it to go between Design and Perform.

- A palette of actors. This example involves two actors: a bee (1x1 square) and a hive (2x2 squares). There is room for six actors in the palette. However, additional rows of up to seven actors each can be easily added using the delete tool (to delete invisible grid characters) and the copy tool. Note: Z-order is important. In each three-high column of squares in the palette, the green stripes, if present, are on the bottom; the frames through which the actors can be seen are on the top; the actors are in between.

- A deleter. Click the deleter. Then click instances to delete them. Note the rollover feedback. Reported Simmer Bug 116: When run on the server, often the rollover feedback persists until you return the cursor to the palette.

- The Stagecast logo. Click it to see our web site in a new window.

Click an actor to select it. The name of the actor appears in bold. When deselected and rolled over, the name appears but not in bold. The name is obtained from the "name" variable of the actor instance in the frame, and if too long, will be clipped.

Click in the white area above the green stripe to drop instances of the selected actor. The hive comes out large even though the palette image was small. The palette image of a large character is an appearance of that character whose name is the name of the appearance you want to appear, preceded by "mini", e.g., to make the "normal" appearance of a large character appear on stage, name its palette appearance "mini normal".

Above the green stripe, every square contains a grid character you can't see. It is only used during Design to make the grid clickable.

Click the Perform/Design switch to go to the Perform stage. It is actually named MX Perform. On the Perform stage, the instances appear exactly where you placed them on the Design stage, and in the same t-order and z-order. The palette is gone and replaced by play controls. There is a wide gray band that you can use, either as is or with the gray filler removed, as a "Custom Controls" area in which you can put "off stage" control characters for your simulation.

On the Perform stage, click Play/Pause to allow/disallow actors to act. It would be easy to provide multiple speeds of play.

Click Restart to restore the actors to their initial states. Restart does not in itself restore any globals that the simulation may have changed. It is the responsibility of the simulation to do that. For example, the Custom Controls area could contain a control character that tested the variable "MX speed" is "Restart".

Click the Perform/Design switch to clear the Perform Stage and return to the Design stage to change the layout.

The Modifiable X framework (not counting Bee and Hive, whose names are actually "MX small proto" and "MX large proto") comprises:
- 2 stages
- 6 characters
- 26 rules
- 7 globals
- 1 jar

It is necessary for every actor to appear in the "MX Actor" jar and to contain a standard rule box of 5 rules. See Bee and Hive for examples. That rule box must come first in the character window, except for rules of layout (such as a rule that prevents dirt from covering a seed) which should fire only on the design stage. For rules of layout, include an MX grid character in the spotlight (or verify that the stage variable of the actor is MX Design).

One layout rule which is very common is included among the five standard rules. It prevents duplicates, i.e., two characters of the same type and appearance in the exact same location. If you want to enable duplicates of a certain actor, disable this rule for that actor. This rule, as found in the bee, works for all 1x1 characters. Large characters require some thought. If you want to disallow any overlap, even partial, use the 1x1 rule as is. (It will display one anomaly though: if you try to overlap two identical actors, the one that is further right will be deleted, or if both have the same h coordinate, the new one will be deleted.) If you want to allow partial overlap of large actors, edit the rule, expand the spotlight to the full size of the appearance, and mark all squares "Don't care". See the Hive for an example of the latter approach.

Only actors can appear in the palette. You may also preload actors, whether or not in the palette, onto the Design stage. They will be copied onto the Perform stage, unless the user deletes them.

To create permanent characters on the Perform stage, either above the green stripe or in the Custom Controls area, be sure they are not actors, i.e., that they do not contain the standard rule box.

All global variables, stages, characters, and jars in the framework have names that begin with "MX" to avoid conflict with names used in sims that are imported into the framework. See the About Box and character window comments for documentation.

Much work left to do (mainly by Jeff, I hope!): Intro stage, Sample Run, Custom Rules, High Score, tell a Friend, etc.