<p>Is there any easy to install/use (on unix) database migration tools like Rails Migrations? I really like the idea, but installing ruby/rails purely to manage my database migrations seems overkill.</p>

I haven't personally done it, but it should be possible to use ActiveRecord::Migration without any of the other Rails stuff.  Setting up the load path correctly would be the hard part, but really all you need is the
```
rake
```
tasks and the
```
db/migrate
```
directory plus whatever Rails gems they depend on, probably
```
activerecord
```
,
```
actviesupport
```
and maybe a couple others like
```
railties
```
.  I'd try it and just see what classes are missing and add those in.
At a previous company we built a tool that did essentially what ActiveRecord::Migration does, except it was written in Java as a Maven plugin.  All it did was assemble text blobs of SQL scripts.  It just needs to be smart about the filenames going in order and know how to update a versioning table.