diff --git a/doc/data/multicountdown.dat b/doc/data/multicountdown.dat
new file mode 100644
index 000000000..a26ac76c5
--- /dev/null
+++ b/doc/data/multicountdown.dat
@@ -0,0 +1,100 @@
+upsec=0.002,color=green,count=1203
+upsec=0.083,color=red,count=3817
+upsec=0.188,color=red,count=3801
+upsec=0.395,color=blue,count=2697
+upsec=0.526,color=purple,count=953
+upsec=0.671,color=blue,count=2684
+upsec=0.899,color=purple,count=926
+upsec=0.912,color=red,count=3798
+upsec=1.093,color=blue,count=2662
+upsec=1.327,color=purple,count=917
+upsec=1.407,color=green,count=1187
+upsec=1.416,color=red,count=3788
+upsec=1.448,color=green,count=1177
+upsec=1.587,color=red,count=3782
+upsec=1.601,color=red,count=3755
+upsec=1.703,color=purple,count=908
+upsec=1.832,color=red,count=3717
+upsec=2.064,color=blue,count=2659
+upsec=2.2880000000000003,color=blue,count=2647
+upsec=2.313,color=green,count=1161
+upsec=2.346,color=green,count=1129
+upsec=2.5580000000000003,color=red,count=3694
+upsec=2.716,color=purple,count=883
+upsec=2.834,color=blue,count=2646
+upsec=2.967,color=green,count=1100
+upsec=3.0740000000000003,color=purple,count=850
+upsec=3.2820000000000005,color=blue,count=2607
+upsec=3.2990000000000004,color=blue,count=2573
+upsec=3.4510000000000005,color=blue,count=2563
+upsec=3.4870000000000005,color=green,count=1089
+upsec=3.7220000000000004,color=red,count=3672
+upsec=3.7580000000000005,color=red,count=3648
+upsec=3.9670000000000005,color=blue,count=2550
+upsec=4.021000000000001,color=green,count=1054
+upsec=4.211000000000001,color=red,count=3640
+upsec=4.455000000000001,color=purple,count=836
+upsec=4.515000000000001,color=red,count=3639
+upsec=4.636000000000001,color=purple,count=801
+upsec=4.818000000000001,color=red,count=3601
+upsec=5.0390000000000015,color=purple,count=770
+upsec=5.268000000000002,color=blue,count=2543
+upsec=5.310000000000001,color=green,count=1039
+upsec=5.319000000000002,color=blue,count=2537
+upsec=5.413000000000002,color=red,count=3568
+upsec=5.517000000000002,color=purple,count=755
+upsec=5.750000000000002,color=green,count=1030
+upsec=5.778000000000001,color=blue,count=2535
+upsec=5.9380000000000015,color=green,count=1008
+upsec=6.101000000000002,color=blue,count=2520
+upsec=6.250000000000002,color=blue,count=2520
+upsec=6.314000000000002,color=green,count=1005
+upsec=6.383000000000002,color=red,count=3551
+upsec=6.546000000000002,color=blue,count=2511
+upsec=6.703000000000002,color=green,count=984
+upsec=6.842000000000002,color=purple,count=721
+upsec=6.986000000000002,color=green,count=976
+upsec=7.229000000000003,color=blue,count=2488
+upsec=7.376000000000003,color=red,count=3547
+upsec=7.567000000000003,color=red,count=3522
+upsec=7.693000000000003,color=blue,count=2454
+upsec=7.869000000000003,color=green,count=937
+upsec=8.051000000000004,color=purple,count=697
+upsec=8.213000000000005,color=purple,count=694
+upsec=8.356000000000005,color=purple,count=658
+upsec=8.379000000000005,color=red,count=3516
+upsec=8.619000000000005,color=red,count=3505
+upsec=8.708000000000006,color=red,count=3479
+upsec=8.773000000000005,color=green,count=929
+upsec=8.809000000000005,color=red,count=3464
+upsec=9.021000000000004,color=purple,count=634
+upsec=9.268000000000004,color=blue,count=2428
+upsec=9.333000000000004,color=purple,count=621
+upsec=9.497000000000003,color=purple,count=606
+upsec=9.539000000000003,color=purple,count=572
+upsec=9.650000000000004,color=green,count=903
+upsec=9.854000000000005,color=blue,count=2400
+upsec=9.963000000000005,color=blue,count=2397
+upsec=10.088000000000005,color=blue,count=2379
+upsec=10.308000000000005,color=red,count=3431
+upsec=10.321000000000005,color=red,count=3398
+upsec=10.542000000000005,color=green,count=894
+upsec=10.752000000000006,color=red,count=3396
+upsec=10.868000000000006,color=purple,count=550
+upsec=10.942000000000005,color=green,count=887
+upsec=11.137000000000006,color=blue,count=2369
+upsec=11.384000000000006,color=red,count=3389
+upsec=11.517000000000007,color=green,count=859
+upsec=11.657000000000007,color=purple,count=516
+upsec=11.707000000000008,color=green,count=853
+upsec=11.809000000000008,color=green,count=828
+upsec=11.904000000000009,color=purple,count=514
+upsec=12.09200000000001,color=red,count=3385
+upsec=12.317000000000009,color=red,count=3359
+upsec=12.37100000000001,color=green,count=789
+upsec=12.58800000000001,color=red,count=3355
+upsec=12.77200000000001,color=red,count=3348
+upsec=12.856000000000009,color=red,count=3346
+upsec=13.103000000000009,color=blue,count=2355
+upsec=13.346000000000009,color=green,count=752
+upsec=13.594000000000008,color=blue,count=2349
diff --git a/doc/data/multicountdown.rb b/doc/data/multicountdown.rb
new file mode 100644
index 000000000..735057627
--- /dev/null
+++ b/doc/data/multicountdown.rb
@@ -0,0 +1,21 @@
+#!/usr/bin/ruby
+$stdout.sync = true
+
+# Simulates some multi-threaded program making progress over time on some set of tasks
+counts = {'red' => 3842, 'green' => 1224, 'blue' => 2697, 'purple' => 979}
+colors = counts.keys
+n = colors.length
+
+start_time = Time::now.to_f
+
+upsec = 0.0
+while counts.any?{|color,count| count > 0}
+  upsec += 0.001 * rand(250)
+  color = colors[rand(n)]
+  count = counts[color]
+  delta = rand(40)
+  count -= delta
+  count = [0, count].max
+  counts[color] = count
+  puts "upsec=#{upsec},color=#{color},count=#{counts[color]}"
+end
diff --git a/doc/data/ping-delta-example.txt b/doc/data/ping-delta-example.txt
new file mode 100644
index 000000000..8e1c7814b
--- /dev/null
+++ b/doc/data/ping-delta-example.txt
@@ -0,0 +1,11 @@
+$ each 10 uptime | mlr -p step -a delta -f 11 
+...
+20:08 up 36 days, 10:38, 5 users, load averages: 1.42 1.62 1.73 0.000000
+20:08 up 36 days, 10:38, 5 users, load averages: 1.55 1.64 1.74 0.020000
+20:08 up 36 days, 10:38, 7 users, load averages: 1.58 1.65 1.74 0.010000
+20:08 up 36 days, 10:38, 9 users, load averages: 1.78 1.69 1.76 0.040000
+20:08 up 36 days, 10:39, 9 users, load averages: 2.12 1.76 1.78 0.070000
+20:08 up 36 days, 10:39, 9 users, load averages: 2.51 1.85 1.81 0.090000
+20:08 up 36 days, 10:39, 8 users, load averages: 2.79 1.92 1.83 0.070000
+20:08 up 36 days, 10:39, 4 users, load averages: 2.64 1.90 1.83 -0.020000
+