Last updated: 6-Jun-15
I've worked hard to combine my <<replace>>, <<timedreplace>>, <<revision>>, <<hoverreplace>> and <<once>> macros, and all their variations, into a single codebase, and included some new variations as well. Here's my combined "Replace Macro Set":

http://twine1.neocities.org/ReplaceMacros.min.js (version 1.1.7)

CSS
The first good news is that you only need this much default CSS for all these macros:

.revision-span-in {
	opacity: 0;
}
.revision-span:not(.revision-span-out) {
	transition: 1s; -webkit-transition: 1s;
}
.revision-span-out {
	position:absolute;
	opacity: 0;
}

The reason I require this CSS is to enable people to modify it to make their own effects. You can, for instance, change this to an instant transition by removing the middle CSS block (with the "transition" property line.)

List of macros
This set includes the following "revision macros":
* <<insert>>, <<replace>>, <<continue>> — triggered by clicking their contents.
* <<timedreplace>>, <<timedinsert>>, <<timedremove>>, <<timedcontinue>>, <<timedcycle>> — triggered by time.
* <<hoverreplace>>, <<hoverremove>> — triggered by the mouse touching their contents, only temporarily.
* <<mousereplace>>, <<mouseremove>>, <<mousecontinue>>, <<mousecycle>> — triggered by the mouse touching their contents, permanently.
* <<once>>, <<later>> — triggered by visiting the passage a certain number of times in the game session.
* <<insertion>>, <<revision>>, <<removal>>, <<cycle>> — triggered by a separate "triggering macro".

It also includes these "triggering macros":
* <<revise>>, <<revert>>, <<randomise>> — hyperlinks.
* <<mouserevise>>, <<hoverrevise>> — sections that the mouse can touch.

Changed syntax
* <<replacewith>>, used to separate sections in <<timedreplace>>, has been replaced with <<becomes>>.
* You can now have multiple sections in most of the revision macros, by separating them with <<becomes>> or <<gains>> macros:

These function just like they do within <<revision>> macros - <<becomes>> replaces the previous section with the next section, and <<gains>> merely appends the next section.
* To reconcile differences between <<replace>> and <<timedreplace>>'s syntax, some macros (currently just the <<replace>>, <<mousereplace>> and <<hoverreplace>> varieties, as well as <<mousecontinue>>) have multiple syntax for specifying sections - the "normal" syntax, where each section is separated by <<becomes>>/<<gains>>, and a "shorthand" syntax, where the first several sections are strings within the opening tag:

The final section must be between the opening tag and the <<endreplace>> macro tag, though.
For most of these, the shorthand strings behave as if the <<becomes>> macro separates them. The exception to this is the "insert" named macros, wherein the strings will behave as if the <<gains>> macro separates them.

New macros
* <<later>> is the antonym of <<once>> - it displays its contained text on the second and subsequent visits.
* <<mousecycle>> creates a section of text that cycles between different versions whenever the mouse touches it. It's similar to <<cyclinglink>> in some respects, though you can't yet easily bind a variable to change when it changes.
* <<timedcycle>> constantly rotates through its sections without stopping. It is similar to <<timedloop>> and may well replace it in future.

Examples

In any of these examples, <<becomes>> can be substituted with <<gains>>.

_{Feel free to report any bugs to @webbedspace.}
Don't use the attached file. It's out of date.