I'd like to know how StackExchange works? Is it just one installation which is divided to different parts or they use a separated installation for each subject? Askubuntu.com, tex.stackexchange.com, superuser.com, etc are integrated and authenticated well. Do they use their software categorizing system for it, Just think: Category=Forum and in this case rewriting URLs for subdomains, Or each of  are based on themselves?
What tools and technologies are used to build the Stack Exchange Network?  See also:
How to view the output of a running process in another bash session? I have left a script running on a remote machine from when I was locally working at it. I can connect over SSH to the machine as the same user and see the script running in ps.   $ ps aux | grep ipcheck myuser  18386  0.0  0.0  18460  3476 pts/0    S+   Dec14   1:11 /bin/bash ./ipchecker.sh   It is simply outputting to stdout on a local session (I ran ./ipchecker.sh form a local terminal window, no redirection, no use of screen etc).  Is there anyway from an SSH session I can view the output of this running command (without stopping it)?  So far the best I have found is to use strace -p 18386 but I get hordes of text flying up the screen, its far too detailed. I can stop strace and then sift through the output and find the text bring printed to stdout but its very long and confusing, and obviously whilst it's stopped I might miss something. I would like to find a way to see the script output live as if I was working locally.  Can anyone improve on this? The obvious answer is to restart the script with redirection or in a screen session etc, this isn't a mission critical script so I could do that. Rather though, I see this as a fun learning exercise. The world I've been playing crashed recently and took the level.dat with it, so I've recreated it, however I have no idea what my seed used to be, and I really don't want to end up with another corrupted game world from exploring with the wrong seed.  How can I recover the seed which was used to generate my world? List of Figures + Beamer? I want to have a List of Figures in my Beamer presentation.  I spent some time searching the web for a solution and only found desperate people telling others that it's not possible, i.e.  or .  I also made some experiments on my own, i.e. "abuse" tocloft to do the job. However, even \usepackage{tocloft} causes pdflatex to fail with ! LaTeX Error: \l@section undefined. (and lying to tocloft by defining the command as empty beforehand doesn't to any good either).  I can't really see why it should be that difficult to make a List of Figures in beamer, since \tableofcontents works flawlessly.   I'm not afraid of doing some coding on my own, but I'm not deep enough into TeX to really understand the magic behind the "List of Figures", "Table of Contents" and alike.  Is anyone out there having suggestions or links that might help me figure this out?  \documentclass{beamer}  % uncomment the following line % to get the error message % `! LaTeX Error: \l@section undefined.`  %\usepackage{tocloft}   % uncomment the following lines INSTEAD % to lie to tocloft % and get the next error message  %\makeatletter %\newcommand\l@section{} %\makeatother %\usepackage{tocloft}  \begin{document}  \begin{frame}{A frame} \begin{figure} \mbox{A} \caption{An 'A'} \end{figure} \end{frame}  \begin{frame}{List of Figures} \listoffigures \end{frame}  \end{document}   EDIT: Solution  Starting from Marco Daniels answer to my question, I modified his code to reflect my needs. Here is what I came up with. Please feel free to comment, improve and reuse this.  \RequirePackage{ifthen}  \makeatletter  \AtEndDocument{%   \clearpage   \beamer@tempcount=\c@page\advance\beamer@tempcount by -1%   \if@filesw   \newwrite\tf@lof   \immediate\openout\tf@lof\jobname.lof\relax   \newwrite\tf@lot   \immediate\openout\tf@lot\jobname.lot\relax   \fi }  \long\def\beamer@makecaption#1#2#3#4{%   \def\insertcaptionname{\csname#1name\endcsname}%   \def\insertcaptionnumber{\csname the#1\endcsname}%   \edef\insertframenumber{\theframenumber}%   \ifthenelse{\equal{#3}{\empty}}{%       \def\insertlistcaption{#2}%   }{%     \def\insertlistcaption{#3}%   }   \def\insertsource{#4}%   \def\insertcaption{#2}%   \ifthenelse{\equal{#1}{figure}}{%       \addtocontents{lof}{\protect\listoffigureformat{\insertcaptionnumber}{\insertlistcaption}{\insertframenumber}{\insertsource}}{}{}%   }{}   \ifthenelse{\equal{#1}{table}}{%       \addtocontents{lot}{\protect\listoftableformat{\insertcaptionnumber}{\insertlistcaption}{\insertframenumber}}{}{}%   }{}   \nobreak\vskip\abovecaptionskip\nobreak   \sbox\@tempboxa{\usebeamertemplate**{caption}}%   \ifdim \wd\@tempboxa &gt;\hsize   \usebeamertemplate**{caption}\par   \else   \global \@minipagefalse   \hb@xt@\hsize{\hfil\box\@tempboxa\hfil}%   \fi   \nobreak\vskip\belowcaptionskip\nobreak% }  \def\listoffigureformat#1#2#3#4{%   \makebox[2ex][r]{#1}%   \hspace{1ex}%   {\usebeamercolor[fg]{bibliography entry author} #2}%   \ifthenelse{\equal{#4}{\empty}}{}{ -- #4}%   \dotfill%   \makebox[2ex][r]{#3}\par% } \def\listoffigures{%   \setlength{\leftskip}{3ex}   \setlength{\parindent}{-3ex}   \@starttoc{lof}% } \def\listoftableformat#1#2#3{\makebox[2ex][r]{#1}\hspace{1ex}#2\dotfill\makebox[2ex][r]{#3}\par} \def\listoftables{%   \setlength{\leftskip}{3ex}   \setlength{\parindent}{-3ex}   \@starttoc{lot}% }  \long\def\@caption#1[#2]#3{   \par\nobreak   \begingroup     \@parboxrestore     \if@minipage       \@setminipage     \fi     \beamer@makecaption{#1}{\ignorespaces #3}{\ignorespaces #3}{\ignorespaces #2}\par\nobreak     \endgroup}  \makeatother Forcefully update to new windows Inverse of a Positive Definite How should I phrase an important question that I need to ask a professor? When needing to ask a professor about something important and potentially delicate, what is an appropriate way to phrase the question or write the email?  Examples include:   Requesting a recommendation letter Asking for exceptions to policy (e.g., ignoring a course prerequisite, rescheduling an exam) Asking if you can do research with them, join a group, get into a program Scheduling a meeting, exam, or defense Letting them know about a change of plans Letting them know about a life event affecting your work or studies (e.g., wedding, funeral, sickness, vacation) Is 'hair' singular or plural? When one says I was washing my hair, is it singular or plural? What is the singular for hair? This is a question from the free Harvard online abstract algebra .  I'm posting my solutions here to get some feedback on them.  For a fuller explanation, see  post.  This problem is from assignment $5$.     Prove directly that distinct cosets do not overlap.   Let $H$ be a subgroup of $G$ and let $a$, $b$, and $c$ be elements of $G$ such that $b\not\in aH$ and $c$ is in both $aH$ and $bH$.  Then there are elements $h$ and $h^\prime$ in $H$ such that $c=ah$ and $c=bh^\prime$.  So $ah=bh^\prime$ and $b=ahh^{\prime -1}$.  But $hh^{\prime -1}\in H$ so $b\in aH$.  This contradicts our original assumption. Therefore, there can be no element in more than one distinct coset.  Again, I welcome any critique of my reasoning and/or my style as well as alternative solutions to the problem.  Thanks. How do I call a .NET assembly from C/C++? Suppose I am writing an application in C++ and C#.  I want to write the low level parts in C++ and write the high level logic in C#.  How can I load a .NET assembly from my C++ program and start calling methods and accessing the properties of my C# classes? How to find out the terminal command of an application? I want to use some applications shown on the Unity Launcher in a terminal, but I need to know the appropriate command to run them. How can I achieve that? Chrome always quit when I click on the X button on a tab, without asking me anything!  Even when I close Chrome he do not alert me if I am willing to relay close it?   Many times it happened that accidentally I clicked on X button. Proving $|P(A\cap B)-P(A)P(B)|\leq \frac{1}4$ Let $A$ and $B$ be two events of a probability space. Prove that  $\displaystyle|P(A\cap B)-P(A)P(B)|\leq \frac{1}4$   I think it's a very challenging problem, and I've made no progress so far ...  Can someone give me a hint ? Definition of complex number In many situations (problems as well as solutions) I encounter the complex number $i$ which many times is defined as $i^2=-1$ instead of $i=\sqrt{-1}$, since it is "more preferred". Does anyone know why? Is it because there are two solutions to the equation $x^2+a=0, \ \ a&gt;0$? Looking for the actual reason of refraction explained precisely without analogies $E$ is a measurable set of finite measure and $1 \le p_{1} &lt; p_{2} &lt; \infty$. Consider the linear space $L^{p_{2}}(E)$ normed by $||.||_{p_{1}}$. Is this space Banach? Unable to post - login problems with Area 51 ... again I recently signed up for Area 51 with my stackexchange network account/ID, verified the account and logged in.  I see the main page  where I confirm that I am logged in.  I click on the discuss link on the black menubar at the top, which takes me to the discussion zone. From here I click on ask question, which asks me to add  a login even though I have already logged in with my stackexchange ID.  Here if I choose the stackexchange login option then it takes me back to the main page, from where the cycle begins again. Torsion on $\pi_1(X)$, $X$ connected and open in $\mathbb{R}^n$ Can the fundamental group of an open connected subset $X$ of $\mathbb{R}^n$ have a torsion element? tasks package: items are in two line with 4 columns and 4 items I write some choice questions into beamer frame, after some research, here is my code:  \documentclass[aspectratio=169]{beamer} \usetheme{Berkeley} \usepackage{tasks,CJK} \begin{document} \begin{CJK*}{utf8}{bsmi} \begin{frame} \transwipe 1.Which one you want to choose? \begin{tasks}[counter-format=tsk[A].,debug=true](4) \task A \task B \task C \task D \end{tasks} \end{frame} \end{CJK*} \end{document}   output with pdflatex:  But I don't want the D choice goto the second line, I want them stay in one line, what should I do? Unable to send e-mail. Contact the site administrator if the problem persists When my web form is filled and submitted, I get redirected to a page that says:     Thank you for submitting.   but theres a red warning box there that says:     Unable to send e-mail. Contact the site administrator if the problem persists.   I think its the SMTP server, but I don't know how to fix that. Anomalous community user activity On the meta home page I noticed the  is listed as doing something, but cannot figure out what it is.  There is nothing on the  or its , but the recent activity is listed with the same timestamp.