Another one of the 7 essential meta questions- what should our logo look like?

Edit: This was originally a discussion both about the logo and about the theme, but now the theme has a separate discussion.

  • 4
    Let's wait until we have chosen our domain name? – Jukka Suomela Aug 17 '10 at 21:18
  • 1
    Does the colour scheme really have much to do with the name? – Greg Aug 18 '10 at 3:18
  • To give an example: if we choose a name like, it might be a very good idea to not choose a red-and-white colour scheme. :) – Jukka Suomela Aug 18 '10 at 9:43
  • 1
    Why ? I'm missing the joke here – Suresh Venkat Aug 23 '10 at 4:48
  • 1
    Cf. – Jukka Suomela Aug 23 '10 at 8:07
  • I second Jukka Suomela’s comment. If the domain name is (current top votes), the logo and design can be anything as Greg suggests. That is exactly what I think is the weak point of the name: it is merely a domain name and does not serve as a theme. If the domain name is e.g. (excuse me for using my own suggestion as an example), the design including the color scheme can and should be consistent with the theme determined by the name. – Tsuyoshi Ito Sep 5 '10 at 18:20
  • 1
    I'd like to break this question into two parts: the logo design and the theme design. While I don't deny that they are related, they are different enough that it's ok to separate out the threads. Thoughts ? – Suresh Venkat Sep 13 '10 at 16:51
  • Sure, splitting sounds fine. We could have a logo design contest for the logo. – Robin Kothari Sep 14 '10 at 15:50
  • I agree to Suresh about breaking the discussion into two parts. Considering that most answers given here are about logo, I guess that a discussion about theme can go to a separate page. Can anyone edit this question and make another discussion for theme? (I cannot do the former because of rep hurdle.) @Suresh, can you do that? – Tsuyoshi Ito Sep 25 '10 at 18:05
  • You can merely create a new question for the theme, and I can edit this one to reflect that. – Suresh Venkat Sep 25 '10 at 18:43
  • @Suresh: Done. It took 2 days to realize your comment, and meanwhile I seem to have gained enough rep to edit a post. – Tsuyoshi Ito Sep 27 '10 at 19:47

13 Answers 13

How about a DFA with 2 states, one labeled "confusion" (or something like that) and the other being a final state labeled "clarity" or "solution" (or something to that effect), and the DFA has only one transition, from confusion to solution, and on the transition arc we write "" in a large font.

  • 9
    How about labeling the states Q and A? Nice, simple symbols but with an obvious meta-interpretation. – Kurt Sep 14 '10 at 23:53
  • Sure.. As my post indicates, I don't have good ideas for what the labels should be. Other suggestions are welcome. Q -> A looks good. – Robin Kothari Sep 15 '10 at 0:15
  • 16
    Q → A is fine, but another idea for labels is ? → !. – Tsuyoshi Ito Sep 15 '10 at 2:45
  • That's also a nice idea. – Robin Kothari Sep 15 '10 at 13:57
  • ? → ! is still meaningful even when rendered very small. Moreover, the dots in the two symbols hark back to the vertices in the state graph. It's a great idea! – András Salamon Sep 18 '10 at 14:18
  • 4
    there should be a loop on the first state – RJK Sep 27 '10 at 20:49
  • One nice thing about ? → ! is that it is using symbols from linear logic (Theory B). So it would be a logo for both Theory A and Theory B. (? and ! are read as "Why not?" and "Of course!"). – Kaveh Oct 18 '10 at 19:40

How do you like this one: ? When you draw this little line between sigma and the infinity symbol, you get a wind-up sigma ;) which I think is a nice symbol for TCS. I used this logo for TCS students' club in my department, but I think it wouldn't conflict.


edit: I made some changes: sigma is now grey and it has two gears instead of the infinity symbol. I didn't change the sigma's font: sans serif fonts deprive it of it's serious mathematical feel, and all serif ones I tried force it to be large (otherwise serifs overlap with the "t"). If someone knows some better font for the sigma, let me know, I will change it. You may also tweak the (GIMP) source:


  • 1
    That's quite a cool logo. – Joe Fitzsimons Oct 2 '10 at 17:13
  • 1
    I like it as well ! – Suresh Venkat Oct 2 '10 at 18:08
  • The idea is great: the symbols on the tape that fades out in both directions, the great big Sigma towering over the tape looking like an FSA. The wind-up infinity doesn't work for me: maybe better a Tex-style limit? The wind-up idea could be preserved by making the infinity out of cogs. – Charles Stewart Oct 3 '10 at 9:20
  • I like the idea. I think the big Sigma is a bit too dominant, though. I wonder if it would be possible to tweak the design so that the Sigma was smaller in comparison with the tape? (You might need to use a different font for Sigma.) – Jukka Suomela Oct 3 '10 at 9:44
  • And a related issue: It's a bit too easy to read it like "Σtcs" instead of "<some decoration> tcs". Using grey instead of black for the big sigma might help; then the "tcs" text would stand out? – Jukka Suomela Oct 3 '10 at 9:47
  • 1
    I think the logo has to fit in a very small space at the top left corner of the website. See MO's logo for example. So it might have to be scaled down a lot. Also, shouldn't our logo contain our name, cstheory? – Robin Kothari Oct 3 '10 at 15:56
  • It looks ok (to me) scaled down on a page (you can see it here: - here it's just a little bit bigger than the MO's one). I could make the tape longer to contain "cstheory". – Karolina Sołtys Oct 3 '10 at 16:57

Why not a Turing Machine? Something like

with the site name written on the tape and something depicting a group of people or a man on his computer inside the head of the TM

Some suggestions for logos:

Of course, we'd have to ask the artist's permission to use any of these.

  • 2
    I like Stolfi's and Dunne's drawings. Not sure how well they work as a logo, though. – Jukka Suomela Sep 14 '10 at 21:53
  • Surely the tape in Dunne's picture could be changed to contain the site name. – Joe Fitzsimons Sep 15 '10 at 0:45
  • This is a very workable collection. – Suresh Venkat Sep 15 '10 at 1:25
  • 2
    Can we ask Randall Munroe to design something specially for the site? – Kaveh Sep 15 '10 at 6:07
  • Of course we can ask him :) - but who knows him ? and is he aware of this site at all ? – Suresh Venkat Sep 15 '10 at 6:46
  • 3
    He visited UIUC a couple of years ago. I'd be happy to ask him. – Jeffε Sep 16 '10 at 1:19
  • +1 for Mr Munroe – Ryan Williams Sep 18 '10 at 2:05
  • 3
    Okay, I asked him. Let's see if he bites. – Jeffε Sep 18 '10 at 6:07
  • 2
    No response from Randall Munroe. Can't say I'm surprised. – Jeffε Sep 25 '10 at 22:43
  • Tsuyoshi's ? -> ! suggestion is definitely in the spirit of xkcd. – András Salamon Sep 28 '10 at 17:39

Proposal 1 (following Jukka's comment)

Proposal 2 (following Kaveh's comment)

Proposal 3 (following Robin's comment)

Proposal 4 (following arnab's comment)

This last one is more sketchy. It now has some visual defects, but they can be easily removed.

  • 1
    Maybe that's a bit too big for a logo? It should fit in the little space we have at the top left corner. – Robin Kothari Oct 18 '10 at 17:01
  • @Robin: I can shrink it down to a reasonable size. Its simple graphics should allow it to be shrinked without loosing details. Here I've presented a bigger version just to give an idea. I wonder if people likes it or not. – Giorgio Camerani Oct 18 '10 at 18:48
  • @Robin: We could add some fade at the left and right ends of the tapes. Also, we may add some further graphics/symbols inside the big box. – Giorgio Camerani Oct 18 '10 at 18:51
  • 1
    I like the ?/! box. No need for the tapes. What if you just take a (scaled-down version, with thicker lines) of the ?/! box and added the text "cstheory" on its right side? – Jukka Suomela Oct 18 '10 at 19:34
  • Nice job, but I found the simpler version (no Turing tapes, two states represented by signs ? and ! on the same level and just one arrow) more appealing. Not only it is a automata theory logo, it is also using signs from linear logic so also covers Theory B. – Kaveh Oct 18 '10 at 19:35
  • agreed. ditch the tape... – Suresh Venkat Oct 18 '10 at 19:44
  • I agree with getting rid of the tapes too. Just one DFA with the word "cstheory" written over the transition arc from ? to ! would be cleaner and yet convey the same message. Also it would be smaller, and so would fit more easily. Maybe the ! state should be the accepting state of the DFA? (i.e., it should have a double circle instead of a single one) – Robin Kothari Oct 18 '10 at 19:49
  • Again, agreed with getting rid of the tapes. Also, maybe change the "!" to a lightbulb? – arnab Oct 18 '10 at 23:19
  • I like this idea. Given the mechanics resp. use of the site, how about including an edge from answer to question? It happens quite regularly that answers create new questions. – Raphael Nov 29 '10 at 8:35
  • @Raphael: Yes I agree with you. I can make a further proposal, adding a "feedback ring" (i.e. just an edge) to the question state. I'm also trying to imagine a less straightforward way to do that (i.e. how to give the same message in a more creative manner). – Giorgio Camerani Nov 29 '10 at 9:35
  • 1
    Maybe: $\{?,!\}^+$ – Raphael Dec 1 '10 at 10:43
  • @Raphael: Cool ;-) I like that! But I'm wondering if these discussions here are still meaningful: isn't the site GUI now definitive? – Giorgio Camerani Dec 2 '10 at 13:57
  • If so then by arbitrary definition. Files can always be changed. – Raphael Dec 2 '10 at 18:00

Another simpler (a little bit funny:) version of $? \rightarrow !$.


  • Before we start designing logos, should we first find out if our logo will be used at all? As far as I can see, the logos of Cooking SE and Web Apps SE were not community designed. (Comments on the logo: Nice. Maybe it should also have "cstheory" somewhere? I always draw my transition arcs above the states, but I guess below works too.) – Robin Kothari Oct 19 '10 at 0:36
  • @Robin Kothari: It is fun even if they don't use them. (If I draw the arc above it won't look like a smiley! :) I agree that it would be much better if we can add cstheory to it (although I am not sure if overlords have accepted cstheory as our name). I played a little bit trying to add cstheory but didn't find a nice way to add it. Feel free to play with it. I can upload my Ipe source if you want, but it is very easy to draw this.) – Kaveh Oct 19 '10 at 0:47

There is no "natural" depiction and design of theoretical computer science and of course it is a matter of taste. But looking at the popular branches of the field, automata theory could provide some simple and easy to recognize images: the name, decorated with circled states, connected via labeled transitions etc.

For the site icon (favicon.ico) the design has to be as simple as possible. We currently have "T/C" which doesn't mean anything. Of the above proposals "TCS" and "?→!" are the two that would seem to work for this specific design element.

I would recommend (in terms of colors and fonts) something similar to StackOverflow or MathOverflow.

What about this?

It's from the book Decision Procedures - An Algorithmic Point of View, so it's certainly copyrighted.

  • A little too big to fit in the header of a page. – Tsuyoshi Ito Oct 11 '10 at 15:36
  • 1
    @Tsuyoshi: Yes, yes it's too big. Its many details do not allow it to be shrinked down to a reasonable size. However, IMHO this picture is great. – Giorgio Camerani Oct 12 '10 at 7:29
  • One could put an image like that in the background, upper left (right) corner. But I do not think this is necessary. – Raphael Dec 2 '10 at 9:31
  • @Raphael: Personally, I'd like to have images like this in the background (of course they should be much more transparent than this). But probably there are few people who agree with such opinion. Also, there would be a copyright issue. – Giorgio Camerani Dec 2 '10 at 13:53
  • Oh, I would not mind if there was a picture in the background, I just think it would not serve any purpose despite (hopefully) looking nice. Since we want to impress with content, not optics, we do not need one. – Raphael Dec 2 '10 at 17:59

For the logo, should the text read CSTheory to match the domain name, or should it be spelled out as Computer Science Theory (or even Theoretical Computer Science)? Even though it would be less informative, I think I would lean toward CSTheory, as it is visually simpler. As for a graphic, I think Jakob's or chazisop's ideas would be nice. The logo text could actually appear as symbols on the TM tape. One consideration is that space is kind of tight in the logo, so it could be hard to do something too elaborate without it looking cluttered.

I find the color scheme on MathOverflow to be hard on my eyes; something a bit more subdued would be nice. Maybe someone has a colleague who works in human factors or graphic design and can help with the color choices?

As far as the other design elements go, the other main items are the backgrounds for the various buttons and tabs. I really like the fact that background image for the tag text on the beta site is an actual tag. It makes it immediately obvious what those are, and I think that's what good design ought to do. I think it's unfortunate that the other sites decided to discard that visual metaphor; I hope we keep it in some form.

  • I definitely think the logo text should read CSTheory to be consistent with the domain name. For a slightly more detailed description on the main page we could have some text analogous to MathOverflow's "Welcome to Math Overflow - A place for mathematicians to ask and answer questions." – James King Sep 14 '10 at 20:20
  • I think we should consider using the spelling "cstheory" or "" instead of "CSTheory" in our logo. – Jukka Suomela Sep 14 '10 at 20:35
  • I would prefer TCS or tcs. – Kaveh Sep 14 '10 at 20:46

For logo, I suggest an illustration (or an idea for one) from Lewis Carrol's books about Alice.


Here is an idea: The disappearing Cheshire Cat, i.e. his eyes and teeth. ? and ! in the eyes, "cstheory" on his teeth, his leaps will look like the arrow in $? \rightarrow !$.

Here's a variation on the emerging consensus, with a little more razzmatazz. I'm also including the source tikz, so in particular someone can figure out how to raise the text a little higher. For some reason I was unable to convert the PDF to an image with enough resolution to display it inline


\begin{tikzpicture}[scale=2.0,node distance=3cm]
  \tikzstyle{every state}=[shade=ball,ball color=white,draw=none,text=black,
                           circular drop shadow] % to get the shadow effect

  \filldraw [fill=gray!20!white] (-0.5,-0.5) rectangle (2,0.8);
  \node[state, ball color=black,text=white]      (s)   {$?$};
  \node[state]         (t) [right of=s] {$!$};

  \draw [->] (s) to [out=60,in=120] (t);
  \draw [decorate,decoration={text along path, text={\ \ \ \ \ \ \ cstheory}}] 
        [yshift=1in] (s) to [out=70,in=110] (t);
  \path (s) edge [loop above]  ();

Note: version updated in response to comments (no loop, and cstheory raised slightly)

  • 1
    Very nice. The only suggestions I have are to make ? and ! a bit bigger so that they're readable when the image is small. Perhaps "cstheory" should be bigger? Or maybe it should be horizontal instead of curved. Not too sure about this, let's see what people think. – Robin Kothari Oct 19 '10 at 4:13
  • Nice job. I agree with Robin, ? and ! and cstheory a bit bigger. curved text is OK, just think it would look nicer if it does not touch the arc. And maybe the states should be a little bit closer to each other. – Kaveh Oct 19 '10 at 6:43
  • And if we are going to have the other arc, maybe we should also add a label to it. (I prefer if it is not there, and there does not seem to be much support for it, RJK's comment above has only 4 votes compared to 14 votes for Tsuyoshi's comment about ? and !.) – Kaveh Oct 19 '10 at 6:54
  • I can remove the arc, but I don't know how to move the text so it doesn't touch the arc. – Suresh Venkat Oct 19 '10 at 7:01
  • 1
    figure updated. no arc, and text was moved. – Suresh Venkat Oct 19 '10 at 14:19

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