Maybe it is a ridiculous question but I want to know exactly what is an upstream program? here in  and other debian packaging documentation mentioned  upstream program.  I want a definition to create upstream from my application.  For example is my web application which is written in java is an upstream?
What is the difference between upstream and downstream when referring to who (or where) to go to as a developer or packager?
On one of my machines I have a process running called "whoopsie". I'm running 12.04 server and never specifically installed anything with this name.  Google seems to imply that it has something to with error logs but I'm not finding too much information. The fact that I didn't manually install it and the 3 other servers I checked did in fact have no such running process OR executable made me a bit confused.  Does anyone know what the "whoopsie" process is?  Does anyone know what packages might have installed it? The server is quite plain, it has a LAMP stack, Samba and print servers and the Nagios NRPE plugin, nothing more installed, just standing there being a nice backup-server.  Some more info:  $ whoopsie -h Usage:   whoopsie [OPTION...]  Help Options:   -h, --help           Show help options  Application Options:   -f, --foreground     Run in the foreground   and  USER       PID %CPU %MEM    VSZ   RSS TTY      STAT START   TIME COMMAND   whoopsie   913  0.0  0.4  24448  2092 ?        Ssl  May07   0:00 whoopsie   and  $ sudo cat /etc/passwd | grep whoop whoopsie:x:107:118::/nonexistent:/bin/false Understanding Group Permissions I'd appreciate help with a couple questions regarding standard file permissions. Assume that I'm not using access control lists.     If a file is associated with multiple groups, must all groups have the same permissions?   If the group permission includes write access, can any member of any group the file is associated with change the file permissions? Can such a person change the file owner?   Say now the file permission is rwxr----- (owner can do everything, but group members can only read). I am in the group associated with the file. I am also the file owner. Which permission am I granted? Read-only, or rwx? How can I find my hardware details? Is there any built-in software or terminal method allowing me to view the hardware profiles on my system? Windows equivalent of such a feature would be Device Manager. Graphing y=x^2 and y=x What happens to global variables declared in a DLL? Let's say I write a DLL in C++, and declare a global object of a class with a non-trivial destructor.  Will the destructor be called when the DLL is unloaded? A borderline between on-topic questions and questions about library recommendation? I have a consideration about new off-topic close reason:     Questions asking us to recommend a tool, library or favorite off-site   resource are off-topic for Stack Overflow as they tend to attract   opinionated answers and spam. Instead, describe the problem and what   has been done so far to solve it.   For example take that question:   It has a close vote with the reason above. But if it would be formed     How to zoom image in an absolute position div to the side?   The answer would be probably also a jQuery plugin or javascript library, but it would follow the patter of most questions about jQuery.  Take that question:   This is the good question about real-life problem. The answer is to use a maven plugin. It is correct, there's no need to reinvent the wheel or rediscover the America.   But  I'm afraid the off-topic text could be misleading and could be misused to close such a questions as that about maven simply because a tool, library or plugin is the answer.   Is it a new guideline that the questions such as cited above should be banned, no matter how they are formed (this would make most how-to-do-in-maven/jquery) questions illegal? Or the close reason should be changed to make more clear what the guidelines are (it's not clear to me now)? Python dictionary: are keys() and values() always the same order? Homeomorphism that maps given points to given points Motivation for Kolmogorov distance between distributions There are many ways to measure how similar two probability distributions are.  Among methods which are popular (in different circles) are:   the Kolmogorov distance: the sup-distance between the distribution functions; the Kantorovich-Rubinstein distance: the maximum difference between the expectations w.r.t. the two distributions of functions with Lipschitz constant $1$, which also turns out to be the $L^1$ distance between the distribution functions; the bounded-Lipschitz distance: like the K-R distance but the functions are also required to have absolute value at most $1$.   These have different advantages and disadvantages.  Only convergence in the sense of 3. actually corresponds precisely to convergence in distribution; convergence in the sense of 1. or 2. is slightly stronger in general.  (In particular, if $X_n=\frac{1}{n}$ with probability $1$, then $X_n$ converges to $0$ in distribution, but not in the Kolmogorov distance. However, if the limit distribution is continuous then this pathology doesn't occur.)   From the perspective of elementary probability or measure theory, 1. is very natural because it compares the probabilities of being in some set. A more sophisticated probabilistic perspective, on the other hand, tends to focus more on expectations than probabilities. Also, from the perspective of functional analysis, distances like 2. or 3. based on duality with some function space are very appealing, because there is a large set of mathematical tools for working with such things.  However, my impression (correct me if I'm wrong!) is that in statistics, the Kolmogorov distance is the usually preferred way of measuring similarity of distributions.  I can guess one reason: if one of the distributions is discrete with finite support -- in particular, if it is the distribution of some real-world data -- then the Kolmogorov distance to a model distribution is easy to compute.  (The K-R distance would be slightly harder to compute, and the B-L distance would probably be impossible in practical terms.)  So my question (finally) is, are there other reasons, either practical or theoretical, to favor the Kolmogorov distance (or some other distance) for statistical purposes? Migrated question's answers can be upvoted twice by the same user was created on Server Fault, answered on Server Fault, I upvoted some of those answers on Server Fault, and then moved by consensus to Super User.  Now that the question is on Super User, I can upvote the same answers I previously upvoted on Server Fault. Is it a wise-decision to buy full-frame lenses for use on an APS-C body? I have a Canon 550D which I've been using for around a year now. I really love it and have learned a great deal with this and the 18 - 135mm kit lens. But now with experience I feel the need to get some better glass. I won't be buying a new body any time soon because I figure investing in some good glass is more important.   As I have looked around, I see quite a few good used L lenses I can get in ebay for good bargain prices. But I know that the EF lenses don't have the same focal length in the cropped sensors. Is it a wise decision to buy these EF lenses or buy the cropped sensor alternatives?  I have the following lenses in mind that I am looking to buy down the line from the canon range over the next several months.  16-35mm f/2.8L, 24-70mm f/2.8L, 70-200 f/4L.  Are these apt choices for cropped sensors? I know most pros with FFs use these but I am a bit skeptic that they will serve the same purpose for me. If so what are the alternatives for this that have almost as good image quality? Proving that without the axiom of choice there is a set with an accumulation point that isn'tthe limit of a convergeant sequence I've been reading the simple parts of Thomas Jech's book on the Axiom of Choice and came across the following proof on page 141. The proof assumes a mathematical model without the axiom of choice.     Lemma. $X$ is D-finite if and only if $X$ does not have a countable subset.       Theorem. There is a set $S$ of real numbers and a real number $a \not \in S$ such that a is in the closure of $S$ but there is no sequence $(x_n)^{\infty}_{n=0} \subset S$ such that $(x_n)^{\infty}_{n=0} \longrightarrow a$.       Proof. Let $D$ be a D-finite infinite set of reals. We claim that the set $D$ must have an accumulation point. To prove this claim suppose that all $d \in D$ are not accumulation points, then let $\{I_n:n=0,1,...\}$ be a fixed enumeration of open intervals with rational endpoints. Assign the least $n$ such that $I_n \cap D={d}$ to each $d \in D$. This makes $D$ countable and by the above lemma gives us our contradiction. So $D$ has an accumulation point $a$. Let $S=D \setminus\{a\}$ and since $S$ is D-finite, every convergent sequence in $S$ is eventually constant.   Could somebody explain this proof? Why is the last sentence true/ Why does this mean every convergent sequence is eventually constant?  I think the following theorem is important     Theorem. There is a model of ZF which has an infinite set of real numbers without a countable subset With markdown, you can use some dashes for headings. For example, this: Hello ---- this is some other text  renders as this: Hello this is some other text This is fine and works well. When I want to quote that text is when the problem arises, since this Markdown: &gt; Hello &gt; ---- &gt; this is some other text  When written down shows well in the preview but not when posted:  Hello this is some other text   As an example, see an screenshot of the preview:    and a screenshot of the posted content, where the ---- becomes a &lt;hr&gt;:  Note a similar bug I also reported: . "The package lists or status file could not be parsed or opened" How do I get object names to appear in the render? In my scene I have multiple objects (30+). In the viewport I have the handy control of selecting (in the Properties Editor) Object> Display> Name and copying to selected.  This is beautiful for diagrams etc. as wherever my view is at whatever distance these labels have been placed instantly, always face me and are always the same size.  How can you get these to display in a rendered view?  Is the ONLY option to manually create a label for each object, get them to track to your camera (Probably have to track to an empty miles behind your camera rotation otherwise they offset if your camera isn't facing exactly front on to an object) and add some sort of scaling property to change depending on how far away you are? How to add some non-standard font to a website? Is there a way to add some custom font on a website without using images,  or some other graphics?  For example, I was working on a wedding website, and I found a lot of nice fonts for that subject. But I can't find the right way to add that font on the server. And how do I include that font with CSS into the HTML? Is this possible to do without graphics? Expectation and variance of the geometric distribution How can one use memorylessness and the  and the  to find the expectation and variance of the geometric distribution?  I will post my own answer, but as always, that shouldn't stop anyone else from posting theirs. What is this weird colon-member (" : ") syntax in the constructor? Prove that if a function $f: X\to Y$ continuous then its graph is closed What's the difference between a shunt resistor and a four-terminal resistor? I want to know if the four-terminal resistor and the shunt resistor are the same.   Is there another use for the four-terminal resistor except measuring current?