diff --git a/.gitignore b/.gitignore
index 61ead86..8b7ef35 100644
--- a/.gitignore
+++ b/.gitignore
@@ -1 +1,2 @@
 /vendor
+composer.lock
diff --git a/PRESETS.md b/PRESETS.md
new file mode 100644
index 0000000..162fee4
--- /dev/null
+++ b/PRESETS.md
@@ -0,0 +1,114 @@
+VfxApply Presets Documentation
+==============================
+
+
+## Preset keys
+
+**Common keys**
+
+| Key               | Type           | Description
+|------.------------|----------------|-------------------------------------------
+| `preset/name`     | *String*       | A description string for this preset
+| `preset/group`    | *String|Null*  | Logical grouping
+| `preset/plugin`   | *String*       | The id of the plugin this preset is for
+| `preset/props`    | *Array*        | Properties used by the plugin
+| `preset/params`   | *Array|Null*   | Parameters for tweaking
+
+## Properties
+
+**ffmpeg**
+
+| Property          | Type           | Description
+|-------------------|----------------|-------------------------------------------
+| `filter`          | *String*       | The filter string, with optional param placeholders
+| `extra`           | *String|Null*  | Extra options to pass on the ffmpeg command line
+| `type`            | *Enum|Null*    | ffmpeg filter type; One of `complex` (default), `audio` or `video`
+
+
+**natron**
+
+| Property          | Type               | Description
+|------.------------|--------------------|-------------------------------------------
+| `project`         | *String*           | Natron project file name
+| `input`           | *String|Int|Null*  | Extra options to pass on the ffmpeg command line
+| `output`          | *String|Int|Null*  | ffmpeg filter type; One of `complex`, `audio` or `video`
+| `framescale`      | *Float*            | Ratio of output frames to input files, 2.0=twice as many out as in=half speed
+
+**executor**
+
+| Property          | Type               | Description
+|------.------------|--------------------|-------------------------------------------
+| `set`             | *Array*            | Define variables
+| `script`          | *Array*            | Define commands
+| `set/%/value`     | *String*           | Set variable % to value.
+| `set/%/escape`    | *Bool*             | If true, the resulting vriable will be escaped
+| `script/%/info`   | *String*           | Info about what this step is doing
+| `script/%/exec`   | *String*           | Command to execute
+| `script/%/parse`  | *Map*              | Parse output from command, see docs for plugin
+
+
+## Parameters
+
+All parameters must specify `label` and `type`. The remaining keys are depending on the
+type of parameter.
+
+**float**
+
+Float parameters need to specify `min`, `max`, `default` and optionally `step`.
+
+
+## Examples
+
+### ffmpeg
+
+    preset:
+        name:   Normalize audio level
+        group:  ffmpeg/audio
+        plugin: ffmpeg
+        props:
+            filter: "dynaudnorm=m={maxgain}:s={compress}"
+            extra: "-c:v copy"
+            type: complex
+        params:
+            compress:   { label:"Compression factor", type:float, min:0.0, max:30.0, default:0.0 }
+            maxgain:    { label:"Max gain factor", type:float, min:0.0, max:100.0, default:10.0 }
+
+### natron
+
+    preset:
+        name:   Apply a CCTV look to the video
+        group:  natron
+        plugin: natron
+        props:
+            project: natron-cctv.ntp
+            reader: Reader1
+            writer: Writer1
+
+### executor
+
+    preset:
+        name: Stabilize video clip (two-pass)
+        group: video
+        plugin: executor
+        props:
+            set:
+                inputtrf: { value:"{%uinput}.trf", escape:true }
+            script:
+                analyze:
+                    info: Getting stabilization vectors
+                    exec: "transcode -i {%input} -J stabilize"
+                    parse:
+                        from: 'stderr'
+                        regex: '/encoding frames \[0-([0-9]+?)\],\s+([0-9\.]+?) fps/'
+                        frame:1
+                        eta:2
+                stabilize:
+                    info: Stabilizing video
+                    exec: "transcode -i {%input} -o {%output} -J transform -y xvid"
+                    parse:
+                        from: 'stderr'
+                        regex: '/encoding frames \[0-([0-9]+?)\],\s+([0-9\.]+?) fps/'
+                        frame:1
+                        eta:2
+                cleanup:
+                    exec: "rm {%inputtrf}"
diff --git a/README.md b/README.md
index 7a380f3..ac063c6 100644
--- a/README.md
+++ b/README.md
@@ -9,11 +9,12 @@ Natron pipeline.
 
 ## Usage
 
-    vfxapply [-i <input>] [-o <output>|-O] [-p <preset>] [-c <key>=<value>]
+    vfxapply [-i <input>] [-o <output>|-O] [-l] [-p <preset>] [-c <key>=<value>]
     
         -i  Set the input file (if omitted, a file picker will be displayed)
         -o  Set the output file (if omitted, a file picker will be displayed)
-        -O  Automatically assign output filename based on input filename
+        -O  Automatically assign output filename
+        -l  List presets
         -p  Select the preset to apply
         -c  Specify parameters for the preset
         -b  Batch mode, input parameter is a list of files
@@ -33,4 +34,25 @@ Examples:
 
 ### ffmpeg
 
+This plugin allows for both video filters, audio filters and complex filters
+to f.ex. normalize audio or generate spectrograms of the audio channes
+
 ### natron
+
+*This plugin is currently broken*
+
+### executor
+
+The executor plugin does as the name suggests; it executes one or more custom
+commands on the input file. The command output can be parsed using regular
+expressions to present the progress.
+
+### melt
+
+The melt plugin uses the MLT library, the same as is used by f.ex. Kdenlive
+to process the media.
+
+### transcode
+
+Transcode uses the transcode tool from transcoder.org. While powerful, it
+works best with AVI files.
diff --git a/check-requirements b/check-requirements
new file mode 100755
index 0000000..01f0a89
--- /dev/null
+++ b/check-requirements
@@ -0,0 +1,31 @@
+#!/bin/bash
+
+function group {
+    echo -e "\e[1m$1\e[0m"
+}
+function good {
+    echo -e "[\e[92m ok \e[0m] \e[32m$1\e[0m"
+}
+function bad {
+    echo -e "[\e[91mfail\e[0m] \e[31m$1\e[0m"
+}
+
+function check {
+    local NAME
+    test -z "$2" || NAME="$2"
+    test -z "$NAME" && NAME="$1"
+    if [ -z "$(which $1)" ]; then
+        bad "$NAME is missing"
+    else
+        good "Found $NAME at $(which $1)"
+    fi
+}
+
+group "Checking for zenity"
+check "zenity" 
+check "dialog"
+
+group "Checking tools"
+check "ffprobe"
+check "ffmpeg"
+check "transcode"
diff --git a/plugins/executor/README.md b/plugins/executor/README.md
index 0555c11..4ac42fa 100644
--- a/plugins/executor/README.md
+++ b/plugins/executor/README.md
@@ -1,23 +1,5 @@
-preset:
-    name: Stabilize video clip
-    group: video
-    plugin: transcode
-    props:
-        set:
-            inputtrf: { value:"{%uinput}.trf", escape:true }
-        script:
-            analyze:
-                info: Getting stabilization vectors
-                exec: "transcode -J stabilize -i {%input}"
-                parse: { regex: '/^encoding frames [0-([0-9]+?)], ([0-9\.]+?) fps/', frame:1, eta:2 }
-            stabilize:
-                info Stabilizing video
-                exec: "transcode -J transform -i {%input} -o {%output}"
-                parse: { regex: '/^encoding frames [0-([0-9]+?)], ([0-9\.]+?) fps/', frame:1, eta:2 }
-            cleanup:
-                exec: "rm {%inputtrf}"
-
-
+Executor Plugin for VfxApply
+============================
 
 ## Scripts
 
@@ -25,6 +7,16 @@ Each script command is named, and will be executed in order of appearance. Error
 will be reported and execution will stop if the exit code is non-zero, using
 the names as logical pointers.
 
+    props:
+        set:
+            <varname>: { value:<expr>, escape:<bool> }
+        script:
+            <step>:
+                info: <string>
+                exec: <commmand>
+                parse: <parse-expr>
+
+
 ### Command lines
 
 Command line uses placeholders.
@@ -40,11 +32,35 @@ Any parameters will also be available:
 
 And you can use `set` to assign stuff to variables.
 
+
+### Setting variables
+
+Setting variables is done using the `set` prop. The core syntax is:
+
+    set:
+        myvarname: { value:"MyValue" }
+
+Additionally, `escape` can be used to flag that the value need to be
+escaped for the command line.
+
+        myvarname: { value:"SomeValue", escape:true }
+
+Variables set this way can be used for the command line, and the same
+expressions can be used to define vars:
+
+    set:
+        tempfile: { value:"{%uinput}.tmp", escape:true }
+    script:
+        first:
+            exec "first --temp-file {%tempfile}"
+
+
 ### Parsing output
 
 To parse the output, add a `parse` key to the command block.
 
         parse:
             regex:    <- expression
+            from:     <- stream for comparison (stdout or stderr)
             frame:    <- index of frame number, or leave out
             fps:      <- index of frames per second, or leave out
diff --git a/plugins/melt/plugin.php b/plugins/melt/plugin.php
new file mode 100644
index 0000000..5e3acf4
--- /dev/null
+++ b/plugins/melt/plugin.php
@@ -0,0 +1,24 @@
+<?php
+
+namespace VfxApply\Plugin\Melt;
+
+use VfxApply\Plugin;
+use VfxApply\Input;
+use VfxApply\Output;
+use VfxApply\Preset;
+
+class MeltPlugin extends Plugin
+{
+    public function getName()
+    {
+        return "melt";
+    }
+    
+    public function applyPreset(Preset $preset, Input $input, Output $output)
+    {
+
+    }
+
+}
+
+return new MeltPlugin();
diff --git a/plugins/transcode/plugin.php b/plugins/transcode/plugin.php
new file mode 100644
index 0000000..7920d8e
--- /dev/null
+++ b/plugins/transcode/plugin.php
@@ -0,0 +1,24 @@
+<?php
+
+namespace VfxApply\Plugin\Transcode;
+
+use VfxApply\Plugin;
+use VfxApply\Input;
+use VfxApply\Output;
+use VfxApply\Preset;
+
+class TranscodePlugin extends Plugin
+{
+    public function getName()
+    {
+        return "transcode";
+    }
+    
+    public function applyPreset(Preset $preset, Input $input, Output $output)
+    {
+           
+    }
+
+}
+
+return new TranscodePlugin();
diff --git a/presets/executor/executor-vidstab-ffmpeg.yml b/presets/executor/executor-vidstab-ffmpeg.yml
new file mode 100644
index 0000000..203fd46
--- /dev/null
+++ b/presets/executor/executor-vidstab-ffmpeg.yml
@@ -0,0 +1,18 @@
+preset:
+    name: Stabilize video clip (two-pass, ffmpeg)
+    group: video
+    plugin: executor
+    props:
+        set:
+            inputtrf: { value:"{%uinput}.trf", escape:true }
+        script:
+            analyze:
+                info: Getting stabilization vectors
+                exec: "ffmpeg -i {%input} -vf vidstabdetect=stepsize=6:shakiness=8:accuracy=9:result={%inputtrf} -f null -"
+                parse: { from: 'stderr', regex: '/^frame=[\s]*([0-9]+)\s/', frame:1 }
+            stabilize:
+                info: Stabilizing video
+                exec: "ffmpeg -i {%input} -vf vidstabtransform=input={%inputtrf}:zoom=1:smoothing=30,unsharp=5:5:0.8:3:3:0.4 -vcodec libx264 -preset slow -tune film -crf 18 -acodec copy {%output}"
+                parse: { from: 'stderr', regex: '/^frame=[\s]*([0-9]+)\s/', frame:1 }
+            cleanup:
+                exec: "rm {%inputtrf}"
diff --git a/presets/executor/executor-vidstab.yml b/presets/executor/executor-vidstab.yml
index 200a2c7..c79eac9 100644
--- a/presets/executor/executor-vidstab.yml
+++ b/presets/executor/executor-vidstab.yml
@@ -2,6 +2,10 @@ preset:
     name: Stabilize video clip (two-pass)
     group: video
     plugin: executor
+    info:   >
+            This preset uses 'transcode' to stabilize the video clip. As transcode has limited
+            support for other output containers than AVI, the resulting file will be an .AVI
+            file.
     props:
         set:
             inputtrf: { value:"{%uinput}.trf", escape:true }
@@ -17,18 +21,3 @@ preset:
                 parse: { from: 'stderr', regex: '/encoding frames \[0-([0-9]+?)\],\s+([0-9\.]+?) fps/', frame:1, eta:2 }
             cleanup:
                 exec: "ls {%inputtrf}"
-#!/bin/bash
-
-#INPUT="$1"
-#OUTPUT="$1.stab.avi"
-#CODEC="-y xvid"
-
-#if [ -e "$INPUT.trf" ]; then
-#    echo "Cache found, not re-calling stabilize..."
-#else
-    # Start the deshake process
-#    transcode -J stabilize -i $INPUT || transcode -J stabilize --mplayer_probe -i $INPUT
-#fi
-
-# Now, stabilize the video
-#transcode -J transform -i $INPUT $CODEC -o $OUTPUT
diff --git a/presets/melt/melt-grayscale.yml b/presets/melt/melt-grayscale.yml
new file mode 100644
index 0000000..25fd42a
--- /dev/null
+++ b/presets/melt/melt-grayscale.yml
@@ -0,0 +1,9 @@
+preset:
+    name:   Turn the video into grayscale
+    group:  melt
+    plugin: melt
+    props:
+        filters:
+            - { type: greyscale, in: ~, out: ~ }
+        
+        # melt test.mp4 -filter greyscale -consumer avformat:output.avi acodec=libmp3lame vcodec=libx264
\ No newline at end of file
diff --git a/presets/transcode/transcode-deshake.yml b/presets/transcode/transcode-deshake.yml
new file mode 100644
index 0000000..165af6c
--- /dev/null
+++ b/presets/transcode/transcode-deshake.yml
@@ -0,0 +1,6 @@
+preset:
+    name: Deshake video clip (single-pass)
+    group: video
+    plugin: transcode
+    props:
+        filter: deshake
diff --git a/src/Application.php b/src/Application.php
index 6428b88..a090f52 100644
--- a/src/Application.php
+++ b/src/Application.php
@@ -12,7 +12,7 @@ class Application
     public function readPlugins()
     {
         $iter = new \DirectoryIterator(
-            __DIR__."/../plugins"
+            APP_ROOT."/plugins"
         );
         foreach ($iter as $dir) {
             if (!$dir->isDir())
@@ -27,7 +27,7 @@ class Application
     {
         $iter = new \RecursiveIteratorIterator(
                     new \RecursiveDirectoryIterator(
-                        __DIR__."/../presets"
+                        APP_ROOT."//presets"
                 ));
         foreach ($iter as $file) {
             if ($file->isDir() || ($file->getExtension()!='yml'))
@@ -83,8 +83,30 @@ class Application
         $this->readPlugins();
         $this->readPresets();
 
-        $opts = getopt("i:o:p:l");
+        $opts = getopt("hi:o:p:l");
 
+        if (array_key_exists('h',$opts)) {
+            printf("Usage:\n");
+            foreach([
+                "%s -h",
+                "%s -l",
+                "%s [-i FILE] [-o FILE] [-p PRESET]"
+            ] as  $example)
+                printf("  ".$example."\n", "vfxapply");
+            printf("Options:\n");
+            foreach ([
+                "-h" => "Show this help",
+                "-i FILE" => "Input filename",
+                "-o FILE" => "Output filename",
+                "-p PRESET" => "Select preset",
+                "-l" => "List presets",
+            ] as $opt=>$info)
+                printf("  %-10s %s\n", $opt, $info);
+            
+            printf("\n");
+
+            return 0;
+        }
         if (array_key_exists('l',$opts)) {
             foreach ($this->presets as $name=>$preset) {
                 printf("%s: %s\n", $name, $preset->getName());
@@ -110,8 +132,8 @@ class Application
         }
 
         $dur = $input->getVideoDuration();
-        printf("Input:  %s %.2fs (%d frames)\n", $input->getFilename(), $dur->seconds, $dur->frames);
-        printf("Output: %s\n", $output->getFilename());
+        printf("Input: \e[1m%s\e[0m %.2fs (%d frames)\n", $input->getFilename(), $dur->seconds, $dur->frames);
+        printf("Output: \e[1m%s\e[0m\n", $output->getFilename());
 
         if (empty($opts['p'])) {
             if (!($preset = $this->selectPreset())) {
diff --git a/src/app.php b/src/app.php
index 860e8e3..f40aa72 100644
--- a/src/app.php
+++ b/src/app.php
@@ -11,5 +11,14 @@ define("DIALOG_SAVEFILE", "savefile");
 require_once __DIR__."/../vendor/autoload.php";
 
 use VfxApply\Application;
+
+// Find the actual root, follow links, and strip the bin part if local
+if (!($script = dirname(@readlink($_SERVER['SCRIPT_NAME']))))
+    $script = dirname($_SERVER['SCRIPT_NAME']);
+if (basename($script)=='bin')
+    $script = dirname($script);
+
+define("APP_ROOT", $script);
+
 $app = new Application();
-$app->run();
\ No newline at end of file
+$app->run();