komradebob on "unexpected '[' in functions.php"

I'm trying to install zenphoto.

Downloaded (2x), unzip/tar'd to a subdir on the web server, browse to http://myserver.com/zenphoto and am rewarded with a blank screen.

Logfile shows:
[Thu Jul 09 14:30:26 2015] [error] [client <redacted>] PHP Parse error: syntax error, unexpected '[' in /export/sites/www.<redacted>.com/web/zenphoto/zp-core/functions.php on line 291

Any ideas?