Downloads: SuperMacro

The SuperMacro addon provides a very much improved interface for writing and using macros. It can do the following, and probably more:
SuperMacro frame shows all 18 global and 18 character macros.
Work around the maximum macro character length of 256 characters (system limit).
Run macros through keybinds and call other macros.
Put an item link or tradeskill recipe into the macro.
Ingame extended LUA code editor.
Action button options.
Many convenient slash commands and script functions. See functions.txt for user-friendly functions and slash commands that can be used in your macros.

Installing SuperMacro:
Backup Bindings.xml and SM_Extend.lua in SuperMacro folder if you added to it. Unzip the files into <WoW>/Interface/Addons . A new directory called SuperMacro will be automatically created, and the files will be extracted there. Create a file called SM_Extend.lua. Be sure to read readme.txt.

Works around maximum macro script length of 256 characters.

Unlimited number of Super macros, which can hold up to 7000 characters.
CAVEAT: Before you can drag SuperMacros into an action bar, you must first create a Regular General Macro. It could be just empty, as long as it exists.

Can even call other macros by name. Use RunMacro(macro), where macro is a number, or a name of a macro inside quotes.
Ex. Keybindings go from RunMacro(1) to RunMacro(36).
Ex. Call other macros like /click MacroClick19 or /click MacroClick_fireball
Ex. Call Super macros like /click SuperMacroClick5 or /click SuperMacroClick_arcane

Put global variables and long functions in SM_Extend.lua, and you can use them in macros.

There is an in-game extend editor. Not the same as SM_Extend.lua. In-game codes are saved in SavedVariables. You don't have to reload UI for these. Max length for these codes is 7000 letters for each macro. You put LUA codes, functions, and variables.

Item linking into macros can be done by Alt-clicking on an item in the container frame, paperdoll, bagslot, and tradeskill frame. Shift-click on item or tradeskill will insert name, and Ctrl-Shift will insert the name inside quotes. Ctrl-Alt-click will insert the tradeskill recipe into the macro.

Allows multi-line blocks of script. start with /script ----[[ and end with ----]] (four dashes each.)
Ex.
/script ----[[
if ( not SuperMacroFrame:IsVisible() ) then
ShowUIPanel(SuperMacroFrame)
else
HideUIPanel(SuperMacroFrame)
end
----]]

Set options regarding macros and action buttons. Options frame can be opened from SuperMacro frame or /supermacro options. Options include hiding names on action buttons, setting macro tooltips, turn off minimap button, auto-replace icons with right spells and items, check cooldown, and changing color for /print and SM_print.

Preview of functions.txt:

Functions and slash commands found in SuperMacro addon that can be helpful in your macros are listed here in alphabetical order.

--Table of Contents
CraftItem( skill, item, count), /craft, /smcraft
echo (see /print)
Fail(message), /fail (also see Pass)
FindBuff(buff [ [, unit], item]), buffed
FindItem(item)
/in seconds[+] command, SM_IN(seconds, command, repeat)
lastActionUsed
Macro (see RunMacro)
Pass(message), /pass (also see Fail)
pickup(bag, slot), pickup(inventory_slot), pickup('item')
/print msg, /smprint, SM_print(msg), echo
PrintColor(r,g,b,msg [,...]), Printc
Printd(msg [,...]), Print
PrintTable(table, rowname, level), Printt
RegisterEventMacro(macro, super, event[,...])
RunBody(longtext)
RunLine(command [,...])
RunMacro(index|macro), Macro, /macro
RunSuperMacro(index|super), /smacro
SayRandom(speech [,...]), /sayrandom, /smsayrandom
send
SetActionMacro(actionid, macro)
SetActionSuperMacro(actionid, supername)
/shift form, /smshift -- for druids, rogues, warriors only
/unequip, /smunequip, /uneq, /smuneq
UnregisterEventMacro(macro, super, event[,...]) (see RegisterEventMacro)
ViewEventMacros() (also see RegisterEventMacro)
--End table of contents

For complete explanations of these functions and slash commands, read functions.txt.

Read readme.txt and functions.txt