diff --git a/appcache.md b/appcache.md
new file mode 100644
index 000000000..b431c3a3a
--- /dev/null
+++ b/appcache.md
@@ -0,0 +1,17 @@
+---
+title: Appcache
+layout: default
+---
+
+### Format
+
+    CACHE MANIFEST
+    # version
+
+    CACHE:
+    http://www.google.com/jsapi
+    /assets/app.js
+    /assets/bg.png
+
+    NETWORK:
+    *
diff --git a/bootstrap.md b/bootstrap.md
new file mode 100644
index 000000000..9b49bb05d
--- /dev/null
+++ b/bootstrap.md
@@ -0,0 +1,33 @@
+---
+title: Bootstrap
+layout: default
+---
+
+### Media queries
+
+    /* Small devices (tablets, 768px and up) */
+    @media (min-width: @screen-sm-min)
+
+    /* Medium devices (desktops, 992px and up) */
+    @media (min-width: @screen-md-min)
+
+    /* Large devices (large desktops, 1200px and up) */
+    @media (min-width: @screen-lg-min)
+
+### Max
+
+    /* mobile < 768px  */
+    @media (max-width: @screen-xs-max)
+
+    /* tablets < 992px */
+    @media (max-width: @screen-sm-max)
+
+    /* desktop < 1200px */
+    @media (max-width: @screen-md-max)
+
+### Columns
+
+    .col-xs-1
+    .col-sm-1
+    .col-md-1
+    .col-lg-1
diff --git a/css-flexbox.md b/css-flexbox.md
new file mode 100644
index 000000000..7b6d4fe5d
--- /dev/null
+++ b/css-flexbox.md
@@ -0,0 +1,56 @@
+---
+title: CSS flexbox
+layout: default
+---
+
+Basic
+
+    .container {
+      display: flex;
+    }
+
+    .container > div {
+      flex: 0 1 auto; /* grow shrink basis */
+    }
+
+Full
+
+    .container {
+      display: flex;
+      display: inline-flex;
+
+      flex-direction: row;         /* ltr - default */
+      flex-direction: row-reverse; /* rtl */
+
+      flex-direction: column;         /* top-bottom */
+      flex-direction: column-reverse; /* bottom-top */
+
+      flex-wrap: nowrap; /* one-line */
+      flex-wrap: wrap;   /* multi-line */
+
+      align-items: flex-start; /* vertical alignment - default */
+      align-items: flex-end;
+      align-items: center;
+
+      justify-content: flex-start; /* horizontal alignment - default */
+      justify-content: flex-end;
+      justify-content: center;
+    }
+
+    .container > div {
+      flex: 1 0 0;
+      order: 1;
+      flex-grow: 0;
+    }
+
+### Centering
+
+    .container {
+      display: flex;
+    }
+
+    .container > div {
+      width: 100px;
+      height: 100px;
+      margin: auto;
+    }
diff --git a/email.md b/email.md
new file mode 100644
index 000000000..529b48e22
--- /dev/null
+++ b/email.md
@@ -0,0 +1,25 @@
+---
+title: Email
+layout: default
+---
+
+### Avoid these
+
+ * position (Yahoo, Gmail)
+ * box-shadow (Yahoo, Gmail)
+ * height (Outlook)
+ * width in p/div (Outlook)
+ * padding in p/div (Outlook)
+ * data-URI (all webmail)
+
+### Basic layout
+
+    <table cellpadding=0 cellspacing=0"
+      <tr>
+        <td width=auto>
+        <td width=600px background=white>
+        <td width=auto>
+
+### Responsive
+
+    @media only screen and (max-device-width: 480px)
diff --git a/express.md b/express.md
index 8ae20b585..f4785ed6d 100644
--- a/express.md
+++ b/express.md
@@ -58,6 +58,12 @@ layout: default
     req.is('html')
     req.is('text/html')
 
+    req.headers
+    req.headers['host']
+    req.headers['user-agent']
+    req.headers['accept-encoding']
+    req.headers['accept-language']
+
 
 ## Response
 
diff --git a/ffmpeg.md b/ffmpeg.md
index cdbe05090..9c3c9773a 100644
--- a/ffmpeg.md
+++ b/ffmpeg.md
@@ -34,9 +34,12 @@ layout: default
 
 ### To web
 
+    # no audio
+    ffmpeg -i input.mov -vcodec h264 -acodec null -strict -2 output.mp4
+    ffmpeg -i input.mov -vcodec libvpx -acodec null output.webm
+
     ffmpeg -i input.mov -vcodec h264 -acodec aac -strict -2 output.mp4
     ffmpeg -i input.mov -vcodec libvpx -acodec libvorbis output.webm
-    # -acodec null
 
     <video width="320" height="240" controls>
       <source src="movie.mp4"></source>
diff --git a/jscoverage.md b/jscoverage.md
index a0a65e691..b401657c2 100644
--- a/jscoverage.md
+++ b/jscoverage.md
@@ -15,7 +15,11 @@ layout: default
 
 The `coverage` task injects your source files (`lib`) with jscoverage hooks, runs `mocha -R html-cov`, then restores later.
 
-    "coverage": "./node_modules/.bin/jscoverage lib && (mv lib lib~; mv lib-cov lib; ./node_modules/.bin/mocha -R html-cov > coverage.html; mv -f lib~ lib)"
+    /* directory */
+    "coverage": "mv lib lib~; (./node_modules/.bin/jscoverage lib~ lib; ./node_modules/.bin/mocha -R html-cov > coverage.html); rm -rf lib; mv lib~ lib"
+
+    /* single file */
+    "coverage": "(cp index.js index.js~; ./node_modules/.bin/jscoverage index.js; mv index-cov.js index.js; ./node_modules/.bin/mocha -R html-cov > coverage.html); mv index.js~ index.js"
 
 ### Run
 
diff --git a/ledger.md b/ledger.md
index e953d566f..a8983a3eb 100644
--- a/ledger.md
+++ b/ledger.md
@@ -190,6 +190,7 @@ CLI interface
                          # [balance] no grand total
     -s, --subtotal       # [balance] show sub-accounts
                          # [other] show subtotals
+    --flat
 
 ### Effective dates
 
diff --git a/nodejs.md b/nodejs.md
index c5aec6fed..c327f453f 100644
--- a/nodejs.md
+++ b/nodejs.md
@@ -138,6 +138,7 @@ layout: default
     });
     proc.on('exit', function(code) { ... });
 
+    // also { stdio: ['pipe', 'pipe', process.stdout] }
     // also { stdio: [process.stdin, process.stderr, process.stdout] }
 
     proc.stdout.on('data', function (data) {
diff --git a/rubiks.md b/rubiks.md
new file mode 100644
index 000000000..620f6409c
--- /dev/null
+++ b/rubiks.md
@@ -0,0 +1,30 @@
+---
+title: Rubiks cube
+---
+
+Getting the cross
+
+ * L (N W C)
+ * line (E C W)
+ * cross (N E W S C)
+
+  `F R U R' U' F'`
+
+Aligning the cross's sides:
+
+ * Nothing aligned
+ * line (N C S)
+ * L (N C E)
+ * ALl are aligned
+
+  `R U R' U R 2U R'`
+
+Aligning the corners:
+
+ * 0 spots ok
+ * 1 spot ok in south-east
+ * 4 spots ok: proceed
+
+  `U R U' L' U R' U' L`
+
+
diff --git a/rubygems.md b/rubygems.md
index 0e7a146c3..3802e4ad0 100644
--- a/rubygems.md
+++ b/rubygems.md
@@ -7,7 +7,8 @@ layout: default
     gem install *.gem           # Install locally
     gem push *.gem              # Upload to rubygems.org
     gem yank foogem -v 0.0.1    # Take it back
-    gem owner -a rico@ricostacruz.com
+
+    gem owner foogem -a rico@ricostacruz.com
 
     gem list                    # List local gems
     gem which rake              # Point to where lib/rake.rb is