Geany filetype definition for PLEXIL plan files (*.ple). Place this in your ~/.config/geany/filedefs directory. You probably wanna add a line "Plexil=*.ple;" to your filetype_extensions.conf as well.

filetypes.Plexil.conf

# For complete documentation of this file, please see Geany's main documentation
[styling=C]

[keywords]
# all items must be in one line
primary=Concurrence Command LibraryAction SynchronousCommand LibraryCall Lookup LookupNow LookupOnChange SkipCondition StartCondition InvariantCondition ExitCondition EndCondition RepeatCondition String Integer Real Boolean Wait In if elseif else endif while for
secondary=INACTIVE WAITING EXECUTING FINISHING ITERATION_ENDED FAILING FINISHED
# these are the doc keywords
docComment=

[lexer_properties=C]

[settings]
lexer_filetype=C

# default extension used when saving files
extension=ple

# MIME type
mime_type=text/plain

# the following characters are these which a "word" can contains, see documentation
#wordchars=_abcdefghijklmnopqrstuvwxyzABCDEFGHIJKLMNOPQRSTUVWXYZ0123456789

# single comments, like # in this file
comment_single=//
# multiline comments
comment_open=/*
comment_close=*/

# set to false if a comment character/string should start at column 0 of a line, true uses any
# indentation of the line, e.g. setting to true causes the following on pressing CTRL+d
	#command_example();
# setting to false would generate this
#	command_example();
# This setting works only for single line comments
comment_use_indent=true

# context action command (please see Geany's main documentation for details)
context_action_cmd=

[indentation]
width=4
# 0 is spaces, 1 is tabs, 2 is tab & spaces
type=1

[build-menu]
# %f will be replaced by the complete filename
# %e will be replaced by the filename without extension
# (use only one of it at one time)
FT_00_LB=_Compile
FT_00_CM=plexilc "%f"
FT_00_WD=