I have a Toshiba laptop, Satellite P200 RT1 which is running Windows XP.  Should I install install the Long Term Support Release of Ubuntu 14.04, or the latest Standard Release of Ubuntu 15.04?  Should I install a different flavour of Ubuntu, such as Xubuntu, Lubuntu, Kubuntu, Ubuntu Mate, etc, given my modest hardware specifications?
I'm thinking about installing Ubuntu Desktop, but I don't know what flavor is the best for my system. What are the minimum and recommended hardware requirements? What kind of CPU? How much memory? Should I have Hardware Acceleration? What flavor should I use?  This is an attempt of a canonical answer. My answers have the &quot;official  requirements&quot;, the recommended are a mix of official sources and opinion based (along with the answer it's told the source). You can comment or edit if you feel that the information is obsolete or incomplete. It is a good rule of thumb that any system capable of running Windows Vista, 7, 8, x86 (Intel) OS X will almost always be a lot faster with any Ubuntu flavor even if they are lower-spec than described below.
Let us say we have the following Makefile  include config.mk  # Generate summary table. results.txt : $(ZIPF_SRC) isles.dat abyss.dat last.dat     $(ZIPF_EXE) *.dat &gt; $@  # Count words. .PHONY : dats dats : isles.dat abyss.dat last.dat  %.dat : books/%.txt $(COUNT_SRC)     $(COUNT_EXE) $&lt; $*.dat  .PHONY : clean clean :     rm -f *.dat     rm -f results.txt   where all the variables are defined in config.mk  LANGUAGE=python COUNT_SRC=countwords.py COUNT_EXE=$(LANGUAGE) $(COUNT_SRC) ZIPF_SRC=testzipf.py ZIPF_EXE=$(LANGUAGE) $(ZIPF_SRC)   Is there any tool available that can expand all the include lines within the makefile so as to produce a bigMakefile? If such a tool does not currently exist, can a python/perl/awk/bash script be cooked up to achieve this goal? Group cohomology intuition Group cohomology is one thing I don't seem to get my head around.  I understand $H^0$ as being the "fixed points" but when it comes to anything higher I have no idea what the notions are meant to be capturing...if anything.  For example I can see that 1-cocycles are homomorphisms with a specific property but that property doesn't seem to mean anything to me...and I think it should!  Is there an intuition or example that explains the meaning or is it just something that "stuck" and seems to work in lots of places? Is it possible for information (like 1 and 0s) to be transmitted faster than light?   For instance, take a rigid pole of several AU in length. Now say you have a person on each end, and one of them starts pulling and pushing on his/her end.   The person on the opposite end should receive the pushes and pulls instantaneously as no particle is making the full journey.  Would this actually work? Create a floating div on top of divs What regular expression will match valid international phone numbers? Make square image Was this an oversight?  Or is it to do with the JVM? I host am ExpressionEngine based website on a single Amazon EC2 instance in the US East (Virginia) region. I use Ubuntu.    The website allows members to post their content, and displays it for other members and for users who are not logged in.   Goal: I need to begin serving the same website across the globe, equally fast to Hong Kong, New York, and Los Angeles.   I considered two solutions:  1.Setting up three separate EC2 instances for three regions: Virginia, Oregon, and Singapore. Use Amazon Rot53 Geo Location to direct traffic to instances based on the browser's IP address.   Pro: the website will load fast for the region.   Contra: these will be essentially three separate websites. Unless I am mistaken?   Setting up one instance in a region equally remote from all three locations: (Ireliand), and boost the server to the highest performance available.    Pro: It will be the same website for all regions.   Contra: it will cost a lot to make it fast enough.   My challenges:   a) I do not know a way to sync server settings, database, and content between multiple Ubuntu instances in real time. If a knowledgeable person could explain to me how to do that, I would be most grateful.   b) I am not thoroughly familiar with all Amazon AWS resources. Does AWS has a built-in method that would allow me to achieve my goal of serving a single PHP / MySQL based membership website across the globe equally fast in all three chosen locations? Regex exec only returning first match Why does $x$ divided by zero not equal $x$? Why does $x$ divided by zero not equal $x$? After all, $x$ is not being divided by anything. Navigation to section/subsection from Beamer headline titles Beamer infolines themes, like CambridgeUS, insert the titles of the current section and subsection in the headline. These titles appear to be clickable (the screen pointer changes as if they were so) but nothing happens when one clicks them.   Is there a way to link the headline titles to the first frame of the corresponding section or subsection? Something like this already works on the theme footline: clicking on the presentation title takes you to the title page.   Edit: MWE  \documentclass{beamer} \usetheme{CambridgeUS}  \setbeamertemplate{navigation symbols}{} \title{Click on Headline} \author{A.~U.~Thor} \institute{X-University} \date{2015} \begin{document} \begin{frame}   \titlepage \end{frame} \begin{frame}[t]{Contents}   \tableofcontents[subsectionstyle=hide]  \end{frame} \section{Section 1} \begin{frame}{Section 1}   \centering \Large Section 1 \end{frame} \begin{frame}[t]{Section 1: Contents}   \tableofcontents[currentsection,hideothersubsections] \end{frame} \subsection{Subsection 1.1} \begin{frame}{Frame 1.1.1}   A frame of subsection 1.1 \end{frame} \begin{frame}{Frame 1.1.2}   Another frame of subsection 1.1 \end{frame}   \subsection{Subsection 1.2} \begin{frame}{Frame 1.2.1}   A frame of subsection 1.2 \end{frame} \begin{frame}{Frame 1.2.2}   Another of subsection 1.2 \end{frame} \section{Section 2} \begin{frame}{Section 2}   \centering \Large Section 2 \end{frame} \begin{frame}[t]{Section 2: Contents}   \tableofcontents[currentsection,hideothersubsections] \end{frame} \subsection{Subsection 2.1} \begin{frame}{Frame 2.1.1}   A frame of subsection 2.1 \end{frame} \end{document} Type safety: Unchecked cast In my spring application context file, I have something like:  &lt;util:map id="someMap" map-class="java.util.HashMap" key-type="java.lang.String" value-type="java.lang.String"&gt;     &lt;entry key="some_key" value="some value" /&gt;     &lt;entry key="some_key_2" value="some value" /&gt;    &lt;/util:map&gt;   In java class, the implementation looks like:  private Map&lt;String, String&gt; someMap = new HashMap&lt;String, String&gt;(); someMap = (HashMap&lt;String, String&gt;)getApplicationContext().getBean("someMap");   In Eclipse, I see a warning that says:  Type safety: Unchecked cast from Object to HashMap  What did I do wrong? How do I resolve the issue? CUDA Driver API vs. CUDA runtime Are there any organised resources available from where I can begin my quantum computing studies? I am a computer science student and am currently searching for resources from where I can learn about quantum computers, quantum computing models, their working principles, their gates and some simple quantum algorithms. For example, when I type ping 8.8.8.8 &amp;, why can we see ping process working? And when I type find / -name '*test*' &amp; , it's also seen on monitor.  Why is that? Is it not really in background? What do Android application permissions mean? When installing an application, the application lists permissions that it needs to perform its  functions.    I am creating this list of the the system defined permissions and a description of what they mean. It is a community wiki so if new permissions are added in the future they can be added to this list. How do I check if a package is installed on my server? I recently installed Ubuntu Server edition 13.10 (Saucy Salamander). But I have run into a bit of problem. At the end of the installation, it asks about several extra packages whether you want them or not, like OpenSSH server and virtual machine host. Here's what I'm looking at:  Now, my problem is that I can't remember if I have checked the &quot;virtual machine host&quot; checkbox. How do I check if my server has the corresponding packages? What packages come with the virtual machine host? Large text files load not working on android How do I parse an ISO 8601-formatted date? Why do votes get locked? I downvoted  and now really can't say why, so I wanted to remove my downvote. However, I get the message:  You last voted on this question yesterday Your vote is now locked in unless this question is edited  Why is this? I don't think I voted on it multiple times, and even when I did, I can change my mind, can't I?