[2021 update] SO moderator timeline, from a template by Najib Idrissi. See http://meta.stackoverflow.com/a/311059

SOmods.tex

\documentclass[tikz]{standalone}   % last update March 2016
\usepackage[utf8]{inputenc}
\usepackage[T1]{fontenc}
\title{Moderator chart}
\begin{document}
\definecolor{rows}{rgb}{0.95,0.95,0.95}
\definecolor{myblue}{rgb}{0.1,0.3,0.9}
\definecolor{mypurple}{rgb}{0.5,0.3,0.7}
\begin{tikzpicture}[scale=0.5]
    % 1 horizontal unit = 1 month, 0 = january 2010
    % "present" = 65 = May 2016  (two months into the future)
    \foreach \i in {1,3,5,7,9,11,13,15,17,19,21,23,25,27,29,31,33,35,37} % each number adds two rows
        {
            \fill[color=rows] (0,\i+1) rectangle (103,{\i+2});
        }
    % each number corresponds to row pos from bottom to top
    \foreach \i in {
            6,  % Michael Myers
            16, % BoltClock
            17, % Brad Larson
            22, % Flexo
            23, % ChrisF
            24, % minitech
            28, % Bohemian
            30, % meagar
            31, % Martijn Pieters
            33, % Jon Clements
            35, % josilber
            37, % Undo
            39, % Aaron Hall
            40, % Bhargav Rao
            41, % deceze
            42, % Andy
            43, % Cody Gray
            44, % Samuel Liew
            45, % Rob
            46, % Baum mit Augen
            47, % Jean-François Fabre
            48, % Machavity
            49, % Makyen
            50, % Stephen Rauch
            51  % Zoe
        }
        {
            % for cosmetic reasons I extended beyond present with a gradient for
            % current moderators
            % this has to be drawn BEFORE the black lines
            \shade [left color=myblue, right color=white]
            (160,\i) rectangle
            (164,{\i+1});
        }

    % employment gradient
    % last number means row position from bottom to top
    \foreach \mod/\mtha/\yra/\mthb/\yrb/\i in
        {
            Adam Lear/1/12/11/15/12,
            animuson/3/15/11/21/25
        }
        {
            \shade [left color=mypurple, right color=white]
            (160,\i) rectangle % gradient start color
            (164,{\i+1}); % gradient stop color
        }

    % format : moderator name/month start/year start/month end/year end
    % months start at 1, year 0 = 2000

    % employment main bars
    \foreach \mod/\mtha/\yra/\mthb/\yrb/\i in
        {
            Marc Gravell/6/10/10/21/1,
            Tim Post/3/13/11/20/8,
            Adam Lear/1/12/11/21/12,
            animuson/3/15/11/21/25,
            Taryn/6/15/10/21/26
        }
        {
            \fill[fill=mypurple]
            ({\mtha + 12*(\yra-8.5) - 1}, \i) rectangle
            ({\mthb + 12*(\yrb-8.5) - 1}, {\i+1});
            \draw (0, \i) -- (173, \i);
        }

    % moderatorship main bars
    \foreach[count=\i] \mod/\mtha/\yra/\mthb/\yrb in
        {
            Marc Gravell/5/9/6/10,
            Bill the Lizard/5/9/4/15,
            Gumbo/2/10/11/11,
            Jonathan Sampson/2/10/3/13,
            Will/7/10/7/13,
            Michael Myers/7/10/11/21,
            SLaks/2/11/11/11,
            Tim Post/2/11/3/13,
            Robert Harvey/2/11/9/19,
            Lasse V. Karlsen/5/11/3/13,
            Kev/5/11/5/13,
            Adam Lear/11/11/1/12,
            NullUserException/11/11/2/14,
            jjnguy/11/11/2/14,
            casperOne/11/11/11/15,
            BoltClock/11/11/11/21,
            Brad Larson/6/12/11/21,
            ThiefMaster/6/12/3/19,
            George Stocker/6/12/10/19,
            Andrew Barber/3/13/3/15,
            Gordon/3/13/11/15,
            Flexo/3/13/11/21,
            ChrisF/3/13/11/21,
            Ry- (minitech)/5/13/11/21,
            animuson/7/13/3/15,
            Taryn (bluefeet)/2/14/10/21,
            Mick MacCallum (0x7fffffff)/2/14/3/16, % resigned on 3/16
            Bohemian/2/14/11/21,
            Jeremy Banks/4/15/11/15,
            meagar/4/15/11/21,
            Martijn Pieters/4/15/11/21,
            Matt/6/15/3/18,
            Jon Clements/6/15/11/21,
            elixenide (Ed Cottrell)/11/15/10/19,
            josilber/11/15/11/21,
            Madara's Ghost (Madara Uchiha)/11/15/1/20,
            Undo/3/16/11/21,
            TheLostMind/3/16/3/19,
            Aaron Hall/11/16/11/21,
            Bhargav Rao/11/16/11/21,
            deceze/11/16/11/21,
            Andy/8/17/11/21,
            Cody Gray/8/17/11/21,
            Samuel Liew/3/18/11/21,
            Rob/3/18/11/21,
            Baum mit Augen/3/19/11/21,
            Jean-François Fabre/3/19/11/21,
            Machavity/7/20/11/21,
            Makyen/7/20/11/21,
            Stephen Rauch/10/21/11/21,
            Zoe/10/21/11/21
        }
        {
            \draw (5, {\i+0.5}) node {\mod}; % mod names left
            \draw (168, {\i+0.5}) node {\mod}; % mod names right
            \fill[fill=myblue]
            ({\mtha + 12*(\yra-8.5) - 1}, \i) rectangle
            ({\mthb + 12*(\yrb-8.5) - 1}, {\i+1});
            \draw (0, \i) -- (173, \i);
        }

    \foreach \txt/\x in
        {
            May 2009/10,
            May 2010/22,
            May 2011/34,
            May 2012/46,
            May 2013/58,
            May 2014/70,
            May 2015/82,
            May 2016/94,
            May 2017/106,
            May 2018/118,
            May 2019/130,
            May 2020/142,
            May 2021/154,
            May 2022/166
        }
        {
            \draw (\x, 0) node {|} node[below=0.3cm] {\txt};
        }
\end{tikzpicture}
\end{document}