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It's the time of the year again, namely it is December 2013, and so we shall now refresh our Community Promotion Ads for the new year. This is a link to the previous thread.

What are Community Promotion Ads?

Community Promotion Ads are community-vetted advertisements that will show up on the main site, in the right sidebar. The purpose of this question is the vetting process. Images of the advertisements are provided, and community voting will enable the advertisements to be shown.

Why do we have Community Promotion Ads?

This is a method for the community to control what gets promoted to visitors on the site. For example, you might promote the following things:

  • the site's twitter account
  • useful tools or resources for the mathematically inclined
  • interesting articles or findings for the curious
  • cool events or conferences
  • anything else your community would genuinely be interested in

The goal is for future visitors to find out about the stuff your community deems important. This also serves as a way to promote information and resources that are relevant to your own community's interests, both for those already in the community and those yet to join.

Why do we reset the ads every year?

Some services will maintain usefulness over the years, while other things will wane to allow for new faces to show up. Resetting the ads every year helps accommodate this, and allows old ads that have served their purpose to be cycled out for fresher ads for newer things. This helps keep the material in the ads relevant to not just the subject matter of the community, but to the current status of the community. We reset the ads once a year, every December.

The community promotion ads have no restrictions against reposting an ad from a previous cycle. If a particular service or ad is very valuable to the community and will continue to be so, it is a good idea to repost it. It may be helpful to give it a new face in the process, so as to prevent the imagery of the ad from getting stale after a year of exposure.

How does it work?

The answers you post to this question must conform to the following rules, or they will be ignored.

  1. All answers should be in the exact form of:

    [![Tagline to show on mouseover][1]][2]
       [1]: http://image-url
       [2]: http://clickthrough-url 

    Please do not add anything else to the body of the post. If you want to discuss something, do it in the comments.

  2. The question must always be tagged with the magic tag. In addition to enabling the functionality of the advertisements, this tag also pre-fills the answer form with the above required form.

Image requirements

  • The image that you create must be 220 x 250 pixels
  • Must be hosted through our standard image uploader (imgur)
  • Must be GIF or PNG
  • No animated GIFs
  • Absolute limit on file size of 150 KB

Score Threshold

There is a minimum score threshold an answer must meet (currently 6) before it will be shown on the main site.

You can check out the ads that have met the threshold with basic click stats here.

marked as duplicate by Grace Note Jan 1 '15 at 3:25

This question has been asked before and already has an answer. If those answers do not fully address your question, please ask a new question.

31 Answers 31

The On-Line Encyclopedia of Integer Sequences

  • Copy of – Grigory M Dec 6 '13 at 12:09
  • 1
    Is there a reason why this isn't linked to the OEIS main page? – user642796 Dec 6 '13 at 12:15
  • 1
    @Arthur I'm not sure, but IMHO search result page better demonstrates its usefulness. – Grigory M Dec 6 '13 at 12:20
  • 3
    What about linking the ad to a random page so each time one clicks on it, a new sequence will be displayed? – Alexander Konovalov Dec 6 '13 at 16:44
  • From an old discussion of (the first version of) this ad: «Wouldn't the ad be more effective if it linked to the relevant search query or straight to the relevant sequence? The sequence is what got me curious and made me click through, after all.» – Grigory M Dec 6 '13 at 18:34
  • 3
    Ah, one of the comments of the sequence that is currently linked to the ad actually says that its first 14 terms appear in the OEIS logo - then it seems to be a perfect candidate to be linked! – Alexander Konovalov Dec 7 '13 at 1:19
  • 4
    This one’s so useful that I even donate a little to them each year. – Brian M. Scott Dec 12 '13 at 21:12


  • Copy of – user93957 Dec 7 '13 at 13:46
  • Why the downvotes? – user93957 Jan 3 '14 at 11:25
  • 1
    I suppose that people don't like that the page explicitly asks for donations. – yo' Feb 12 '14 at 12:53
  • 7
    Or because noone can draw beautiful curly braces like this with a mouse. – Phira Feb 19 '14 at 7:37 -- open access to over 800 000 e-prints

  • Copy of – Grigory M Dec 6 '13 at 12:12
  • 5
    Perhaps it is time to update the number to 900k? – Asaf Karagila Dec 7 '13 at 22:54
  • @Asaf Well, arXiv doesn't yet have 900k preprints... – Grigory M Dec 9 '13 at 8:38
  • 1
    True. But by 2014 it ought to have that amount. This thread is for ads for 2014 (whether or not they appear now is a whole other thing)... Anyway, I think it is worth being prepared. :-) – Asaf Karagila Dec 9 '13 at 8:50
  • 2
    @AsafKaragila: finally, it's time to update: I've just seen it reporting 900,267 e-prints. – Alexander Konovalov Dec 18 '13 at 21:42
  • 2
    Huzzah! Next year: 1M. – Asaf Karagila Dec 18 '13 at 21:43
  • Still says "800 000" ... – SamB Jan 10 '14 at 20:12
  • If someone could please update the number... (I've left a comment for Yi Jiang in the last year's thread but he haven't answered.) – Grigory M Jan 10 '14 at 20:16
  • 4
    I still had the GIMP .xcf file from last year's fix, so I went and updated it again. – Ilmari Karonen Jan 26 '14 at 0:17
  • 1
    Ps. Here's the .xcf file, in case someone else wants to update it for 1M. :) The font used is Aller. – Ilmari Karonen Feb 7 '14 at 21:16
  • 1
    994,223 preprints as on Dec 8th so perhaps this file will be useful soon :) – Alexander Konovalov Dec 8 '14 at 20:43
  • 1
    @AlexanderKonovalov Good timing too, since the 2015 ads collection is just around the corner. Let's hope ArXiv will keep adding exactly 100,000 items every year. – user147263 Dec 8 '14 at 20:54
  • 1
    @Behaviour: and now they have one million! See also the plot at – Alexander Konovalov Dec 30 '14 at 10:58


  • Copy of – user93957 Dec 7 '13 at 13:47
  • That's not what I call "Free mathematics software" ... – SamB Jan 10 '14 at 20:11
  • @SamB: What's not free about it? – Assad Ebrahim Mar 18 '14 at 13:57
  • @AssadEbrahim: Does it seem to fit to you? – SamB Mar 20 '14 at 20:43
  • 2
    @SamB: Interesting. They've changed their license recently it appears. Quoting from the Wikipedia link: while the source code is licensed under the terms of the GNU General Public License, the translation files, installers, and web services are licensed under non-GPL-compatible terms. Commercial use is prohibited without the purchase of a separate license. It has been noted by the maintainer of the software in Debian GNU/Linux that these terms, a change from earlier releases, prevent the resulting combined work from being considered free software and may be nondistributable. – Assad Ebrahim Mar 22 '14 at 0:22
  • @SamB: Thanks for the reference – Assad Ebrahim Mar 22 '14 at 0:23
  • 1
    @AssadEbrahim: Ah. After looking at the terms shown on the site, the idea of it being in Debian naturally didn't cross my mind... I wonder how hard it'd be to get a free fork caught up on the translations? – SamB Mar 24 '14 at 16:53



  • I miss "\label{aa}" and "\eqref{aa}" functions, and also possibility to use some user-defined macros, e.g. \newcommand{\RR}{\mathbb R}. But nice! – Skeeve Jan 18 '14 at 12:13
  • 4
    NOTE: you can customize MathJax with your own macros in Settings->Extensions->MathJax->Tex configuration. See – benweet Jan 18 '14 at 12:35
  • thanks, I didn't dig deep enough in the settings! – Skeeve Jan 20 '14 at 23:04
  • downvoter???!!! – benweet Feb 15 '14 at 17:11

GAP - Group, Algorithms and Programming

ProofWiki - online compendium of mathematical proofs.

  • Copy of – user93957 Dec 7 '13 at 13:56
  • 6
    I’m not terribly keen on the idea of recommending this site: I find the house style rather opaque, verging on obfuscatory. – Brian M. Scott Dec 12 '13 at 21:09
  • 1
    @BrianM.Scott it seems to me like they copied their style from TVtropes. – guest196883 Jan 22 '14 at 23:51
  • They also have a bizarrely convoluted and invasive sign-up process requiring you provide a CV and personal details such as your real name and phone number to verify your identity. – Jack M Feb 20 '15 at 9:43

Wolfram Alpha

  • 5
    lol... I never thought of advertising Wolfram since it is too popular. – user93957 Dec 12 '13 at 19:02
  • 2
    See also previous discussion @ – Grigory M Dec 13 '13 at 8:41
  • And it's still valid: free ads for a commercial product, while there are good free CAS. I downvote. – Jean-Claude Arbaut Dec 24 '13 at 9:23
  • 9
    @arbautjc I think wolframalpha isn't mainly a CAS, but something special, because of you don't need to know a bit of syntax to use it while for most CAS you need to know the correct syntax. Furthermore the basic functions of wolframalpha are free – Dominic Michaelis Dec 24 '13 at 15:30


  • Copy of – user93957 Dec 7 '13 at 13:49
  • 1
    Could the $3$ downvoters explain their act? – user93957 Dec 21 '13 at 18:57
  • 6
    At least I can explain mine: free ads for commercial product. No way. – Jean-Claude Arbaut Dec 24 '13 at 9:28
  • @arbautjc This is not a commercial product. – user93957 Dec 24 '13 at 12:29
  • Really? Then it's probably by mistake they put a "Pricing" link. – Jean-Claude Arbaut Dec 24 '13 at 12:35
  • 3
    @arbautjc The pricing link is for upgrading one's account, the main features of writeLaTex are free. – user93957 Dec 24 '13 at 12:47
  • 2
    Yes, like WolframAlpha and many others, the free stuff is here to push people to buy the commercial stuff. As I said, I won't upvote free ads to a commercial product. – Jean-Claude Arbaut Dec 24 '13 at 12:52
  • 1
    @arbautjc Your reason isn't viable. Community promotion ads are for: $$\begin{align} \circ & \text{the site's twitter account }\\ \circ & \text{useful tools or resources for the mathematically inclined}\\ \circ & \text{interesting articles or findings for the curious}\\ \circ & \text{cool events or conferences}\\ \circ & \text{anything else your community would genuinely be interested in}\\ \end{align}$$ Wolfram and writeLaTeX are perfectly compatible with that chart because of the second and last reasons. – user93957 Dec 24 '13 at 12:59
  • 17
    It's not prescribed by MSE that ads are only for free sites. But it's my choice that I will downvote any ads for commercial ones. You asked for the reasons of downvoters, I gave you mine. – Jean-Claude Arbaut Dec 24 '13 at 12:59
  • 1
    @arbautjc "the free stuff is here to push people to buy the commercial stuff." - not necessarily. – user93957 Dec 24 '13 at 13:00
  • 7
    This discussion would never end. I perfectly accept, and understand, that we disagree. I'm not in the least trying to convince you. And on the other hand, there is no issue for you, since there are already more than enough upvotes for this one. – Jean-Claude Arbaut Dec 24 '13 at 13:04
  • @arbautjc Je suis d'accord avec votre dernier commentaire :-) (Big thanks to G-translator) – user93957 Dec 24 '13 at 13:05
  • I've used this one a lot. – DatEpicCoderGuyWhoPrograms Jul 16 '14 at 1:06

Current Mathematics bounties

  • 1
    +1, but, please--nicer theme! It would be great to have a different theme. Someone with free time (like anyone has that) should write a similar script but with a theme more conducive to the MSE theme. – apnorton Dec 12 '13 at 2:09
  • 10
    Yeah: "There are currently less than $e^\pi$ active bounties, worth $\pi^{e^2}$" – draks ... Dec 12 '13 at 12:28
  • I'm pretty sure this isn't a valid ad anyway, since it fails the "[image must] be hosted through our standard image uploader (imgur)" requirement (not to mention the size requirement). – Ilmari Karonen Dec 14 '13 at 12:23
  • 5
    @IlmariKaronen The image works perfectly on Apple.SE even if it size is greater than 220x250 (it get displayed at the correct size through) and if it isn't hosted by imgur. – user93957 Dec 14 '13 at 12:25
  • b.t.w: The add shows great results for its first appearance: – user93957 Dec 17 '13 at 12:34
  • 1
    Somewhat-significant bug: if you're not logged in, this redirects to the plain front page. – Nick T Jan 13 '14 at 21:21
  • 1
    You may want to consider allowing https for this: – Oded Feb 18 '14 at 14:42
  • How does this ad update? Does someone need to change it manually? Is there a system periodically checking the bounties and updating the image? It seems to be out of date at the moment; there are 57 bounties out right now. – user2357112 May 5 '14 at 10:52
  • but can this be updatable, like this really shows exactly how many bounties are there and the total reputation awarded for answering them all? – user198454 Jan 11 '15 at 10:38


  • Copy of – user93957 Dec 6 '13 at 17:15
  • Could the downvoter explain his act? – user93957 Dec 17 '13 at 12:35
  • 10
    I upvoted this, but IMO, the biggest weakness of this ad has always been that it says nothing about what Khan Academy is. If you don't already know what it's about, there's nothing in this ad to tell you why you should click it (or upvote it, for that matter). – Ilmari Karonen Dec 28 '13 at 22:32
  • 7
    Yes, this ad is completely uninformative ... – SamB Jan 10 '14 at 20:08
  • It doesn't have to--it's Khan Academy, probably the most popular site listed here. (Plus, it's more informative than that WolframAlpha ad...) – Steve S Aug 2 '14 at 1:54

A beautiful, free online graphing calculator

  • 4
    Made in Mathematica for a lack of proper tools (not proudly). Please feel free to improve the post and especially the graphic (or down/up vote). The tool itself is very useful (at least to me). I added their standard tag to the found original image source and ensured dimension conformance. – J. W. Perry Dec 22 '13 at 3:54
  • 3
    Really valuable for its ability to create interactive Cartesian demos that can be shared over the Internet. – hardmath Feb 1 '14 at 23:35

Crypto Stackexchange


  • I wanted to start such a site myself. I am so happy it already exists. I hope it will grow further. – Erel Segal-Halevi Apr 23 '14 at 15:43
  • 1
    @ErelSegalHalevi I'd be very glad if you could work/contribute to the site as well! – Jernej Apr 28 '14 at 8:54
  • I think the exercises should be divided accordingly to the subject to which they belong to. Just in Probability, there are only 9 exercises but from completely different subjects, I think. Maybe it could be ordered by subjects, like in a college degree. In probability section, you could have those considered to belong to introductory courses, then those of intermediate and advance level. It would really help if each section was structured as the branches of probabilities are in university degree all around the world. Good Luck! ;) If you need some help I may try, though I know very little. – An old man in the sea. Jul 29 '14 at 9:47
  • I'd like to give the following link: a full set of solution to Dummit and Foote's Abstract Algebra (2nd edition) published online on wordpress. I'm not going to copy out all the solutions, but throwing a link up there would be a nice step. – Alfred Yerger Dec 23 '14 at 3:59

AMS Graduate Student Blog - Read and write about topics that matter to you.


  • Copy of – user93957 Dec 7 '13 at 13:49
  • 12
    I still dislike "funnest", but perhaps it only bothers me. – Austin Mohr May 7 '14 at 22:59
  • @Austin Mohr I agree, might be best to replace funnest with best. Not very imaginative but better. – bobbym May 12 '14 at 23:44

Stack Exchange Q&A site proposal: Puzzling

  • Considering how you lot already have puzzle and recreational-mathmatics tags, I imagine the Puzzling SE would fit in quite well here. – IQAndreas Feb 16 '14 at 5:34

Scientific Literature Digital Library & Search Engine

Lollipop: A New Advanced TeX Format

  • thank Dr. Khalighi – SKMohammadi May 12 '14 at 12:34
  • Really pretty logo. – bobbym May 12 '14 at 23:46


  • 15
    I like the idea of promoting Academia.SE. But 3 differently styled texts (white on black, pink on white, black on white) looks... somewhat unprofessional, maybe. Oh, and 19 words (3 words «academia» included) seems to be too long for an ad. – Grigory M Dec 6 '13 at 18:42
  • Okay, I will try to ameliorate it! @GrigoryM – user93957 Dec 6 '13 at 18:43
  • 4
    I'd prefer version without that black frame (with its text) and without pink font, maybe? – Grigory M Dec 6 '13 at 18:43
  • 4
    As I commented last year, I still think "Rocking your world" is in poor taste. – Austin Mohr Dec 16 '13 at 3:12

FactorDB: an integer factorization database

  • 1
    Rather minimalistic, if anyone has an idea to improve... – Jean-Claude Arbaut Dec 21 '13 at 10:02


  • 7
    Free ads for commercial product. I downvote. – Jean-Claude Arbaut Dec 24 '13 at 9:27
  • @arbautjc Again, we disagree. – user93957 Dec 24 '13 at 13:10
  • I know :-) There is also WolframAlpha below. – Jean-Claude Arbaut Dec 24 '13 at 13:11

arXiv Analytics: specialized web portal dedicated to reading & discussing arXiv eprints

  • 2
    It's either very late or a bit early to post new Community Ads proposals... The history suggests that we are just about to enter the new round (2015 ads). – user147263 Dec 8 '14 at 6:48


  • 26
    I dislike this advert for two reasons. Firstly, it is implying that I, as a user of this site, use something I do not use. Secondly, it tells people that it is "okay not to know your functions!". This is (arguably) true when you get a certain level, but most students here will not be at that level yet... Also, being allowed to not know your functions is then extended (in the students minds) to "not knowing your derivatives" and so on until we get to "not knowing your definitions". – user1729 Dec 17 '13 at 11:01
  • 6
    (I should say thought: I don't mind the site itself being advertised, just not with this advert.) – user1729 Dec 17 '13 at 11:35
  • 5
    Upper half with text over formulas looks somewhat... messy, IMHO. – Grigory M Dec 21 '13 at 18:14
  • 2
    (And maybe this one also has just too many words...) – Grigory M Dec 21 '13 at 18:16
  • 4
    "Power up your memory with Digital Library of Mathematical Functions!" or brain implant jokes are better. – Frenzy Li Dec 26 '13 at 14:46
  • @user1729 I'm the author of this ad, over in Physics. I'm a research physicist and I can say with confidence that, while it is not OK not to know that e.g. this formula exists, it is OK not to memorize its exact details up to the very last constant. I think it is much more important to learn to know and use these resources - the DLMF, and previously A&S - than to memorize exactly the form of every relation you've ever used. – E.P. Jan 17 '14 at 14:15
  • That said, I'm open to suggestions on how to improve this advert, both on the graphical and the content front. @FrenzYDT.'s text, for example, could do; care to suggest a layout? – E.P. Jan 17 '14 at 14:16

Follow us on Twitter!

  • This is an example ad to demonstrate, with the site's twitter account. For the past two years it has not stayed above the 6 vote threshold, which is perfectly fine when the community has more relevant items to show each other. – Grace Note Dec 6 '13 at 11:36
  • 5
    what is bad with the Twitter account? – dwarandae Jan 23 '14 at 22:59
  • 5
    @dwarandae That's the wrong question. The correct question is: What is good about promoting it? There's much more interesting stuff to promote here. – yo' Feb 12 '14 at 12:51

enter image description here

  • If anyone has a better picture for the ad of please edit my post. – user103816 Apr 21 '14 at 3:27
  • 3
    I don't really see the reason to promote the Internet Archive on math.SE; the vast majority of the other advertisements are very focused towards math or related topics. (Also, is this just a screenshot of the current state of the website?) – user61527 Apr 21 '14 at 3:48

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