Authors of accepted papers will receive reviewer comments by email. Please take them into account carefully when preparing your camera-ready paper for the proceedings.

The final paper and the signed copyright form are due by the camera-ready deadline:

Furthermore, please note that we expect to receive at least one non-student full conference registration for each paper (details will be communicated later).

The Middleware 2021 Proceedings will be published under the ACM (Association for Computing Machinery) copyright, under their usual copyright and permissions policy.

ACM Copyright Form to be Completed

Authors of accepted papers need to log-in to the HotCrp site corresponding to the track that they submitted their paper to. On the submission page for their paper, there will be a link to the ACM e-Rights form that will need to be filled and submitted (this is the same page as for the camera-ready submission).

Note: Usually, only one ACM copyright form is needed, and it can be signed by the lead or contact author. A second form may be requested from co-presenters depending on any US or foreign government affiliations. The ACM Copyrights-Permission office will notify you if a second form is needed.

Requirements for Preparing Your Final Paper Version

ACM provides a template for Microsoft Word and a template for LaTeX. However, ACM is currently in the process of revamping its Word template, and therefore, an interim template is used in the meanwhile. We highly recommend that the LaTeX template be used.

Microsoft Word Instructions

Please download the ACM “Interim Template” Word document (Interim layout.docx) from ACM here. There is also a sample PDF file produced with the Word template. We strongly encourage you to review the sample file above so you will be aware of the mandatory sections, copyright strip information (see next step), formatting requirements, font requirements, font sizes, and spacing required for the final version.

The correct ACM Middleware 2021 copyright-permission notice (generated through HotCrp) needs to be inserted in the sample files above (page 1, bottom of column 1) before you submit your final version. A custom DOI URL (also generated through HotCrp) will also need to be included.

This statement must be in 7 point Libertine font, with the first paragraph text justified, with the venue acronym/track (e.g., Middleware ‘21, or Middleware Industry ‘21) in italics. Refer to the “Interim-layout.docx” sample file to view how the ACM copyright statement should appear -- you should preserve the original formatting.

LaTeX Instructions

Template: Please use the sigconf proceedings template from the ACM Master article template for LaTeX (acmart class) for your submission (under the LaTeX Authors section). Please follow the instructions given on the page, and please have a look / start from the sample file “sample-sigconf.tex” in the acmart package. Even if you have already downloaded the package for another conference, you should download it again as ACM often makes changes to their template and publishes new versions. If you submit a paper using an outdated version of the template, you might be required to update to a newer version.

Fonts: Type 1 or TrueType fonts must be used (this will usually happen by default). Type 3 fonts are not permitted. TrueType fonts are permitted, but will be tested for any problems which may need to be rectified. For help on obtaining the correct type of fonts, see this hint in the ACM FAQ list. Note: in rare cases, PDFs generated with pdflatex will not contain embedded fonts. This most often occurs when vector images included in paper do not themselves embed their fonts. If we find problems with your PDF, and you are unable to submit a revised version with correctly embedded fonts, we may have to take a less desirable and less safe route: that you submit a PostScript (PS) version, from which we produce PDF.

Camera-ready copyright header: the ACM copyright form will provide a block of LaTeX code to be included in the “Rights management information” section of the header. Please double-check that your produced document matches the copyright info details found in HotCrp, and that you have included your full DOI URL.

Other Information:

Please continue reading for additional information on preparing your final paper.

Font size and page limit

Font sizes of 10 pt and 9 pt are acceptable (unlike original submissions which required a font size of 10 pt only).

The following page limits applies:

  • Research Papers: 12 pages of technical content, including text, figures, and appendices, but excluding any number of additional pages for bibliographic references.
  • Industry Papers: 6 pages of technical content, including text, figures, and appendices, but excluding any number of additional pages for bibliographic references.
  • Workshops:
    • M4IoT ‘21 – Research papers: 6 pages of technical content, including text, figures, appendices, and references.
    • M4IoT ‘21 – Position papers: 4 pages of technical content, including text, figures, appendices, and references.
    • WoC ‘21: 6 pages of technical content, including text, figures, appendices, and references.
    • DICG ‘21: 6 pages of technical content, including text, figures, appendices, and references.
    • WoSC ‘21: 8 pages of technical content, including text, figures, appendices, and references.
    • DIDL ‘21 – Research and industry papers: 6 pages of technical content, including text, figures, and references, plus up to 2 pages of appendices if need be (total 8 pages).
    • DIDL ‘21 – Position papers: 4 pages of technical content, including text, figures, appendices, and references.
    • DIDL ‘21 – Extended Abstracts: 1 page of technical content, including text, figures, and references.
  • Demos and Posters: 2 pages of technical content, including text, figures, appendices, and references.
  • Doctoral Symposium:
    • For early-stage research students: 2 pages of technical content, including text, figures, appendices, and references.
    • For late-stage research students: 4 pages of technical content, including text, figures, appendices, and references.
    • Your category (early-stage or late-stage) cannot change between the initial and camera-ready submission.

Page size

The page size for this ACM publication is US Letter Portrait (8.5×11 inches). Submissions that do not conform to the ACM standards, templates, and formats will be returned to the author for corrections and/or alterations.

File naming scheme

Name your final submission according to the ACM convention: firstauthorname.pdf (e.g. JanetSmith.pdf) using the name of the first author.


Must be in Initial Caps Meaning First Letter of the Main Words Should be Made Capital Letters. Ex: note the Capital Letter “M” in Must, Meaning, and Main, the Capital Letter “C” in Caps and Capital and the Capital Letter “L” in Letter and Letters.

For poster and demo papers only: please prefix your title with "Demo Abstract:" or "Poster Abstract:".

Note: Experience papers should bear the prefix ‘Experience Paper:’ in the title.

Authors’ complete names, email, affiliation and affiliation location

Prior to submitting, be sure to update the final version of your PDF to include all authors full names, and correct affiliation names, location, and other information under the title of the paper. See the first page of the ACM sample pdf.


Authors must include a brief summary (abstract) of their work in the first section of their submission after the title, authors, and affiliation information on the first page. See the first page of the ACM sample pdf.


Authors must include all works cited in their submission in a References section at the end of the paper or extended abstract. See page 4 of ACM sample pdf. Also refer to the ACM citation style and reference formats.

ACM Classification Sections

The Categories and Subject Descriptors and Keywords are mandatory by ACM on the first page of your submission after the Abstract. See the first page of the ACM sample pdf for information about how these two sections should appear in your submission.

Read this section carefully. Your selections for the three sections are mandatory on the submission page when submitting your final version.

Categories and Subject Descriptors (Mandatory for the first page of your paper): Make sure that your selection included on the first page of your paper is also chosen accordingly on the submission page. Click here for information on the ACM Computing Classification Scheme. The new templates enable you to import required indexing concepts for your article from the ACM Computing Classification System (CCS) using an indexing support tool found in the ACM Digital Library (DL) which generates the necessary LaTeX code once you have selected your terms.

Keywords: This section is your (author) choice of terms that you would like used to index your work.

Bad Breaks

Be sure you do not have bad page breaks or bad column breaks. One example of a bad column break is a widow, which occurs when the last line of a paragraph that begins at the bottom of one column appears by itself at the top of the next column). If this happens, tighten the previous column to bring it back, or force an additional line of text over to the next column.

Also make sure that Section and Sub-section headings have at least two lines of body text below them when they appear at the end of a page or column.

Third Party Material

In the event any element used in your material contains the work of third-parties, it is the author/presenter’s responsibility to secure any necessary permissions and/or licenses, and the authors will provide the same permissions in writing to the ACM. If the copyright holder requires a citation to a copyrighted work, it is the authors’ responsibility to include the correct wording and citations to the copyrighted material in their submissions.

Images and Figures

Below are some recommendations to ensure good print reproduction of the images, figures, and illustrations utilized in your submission.

Colors and Black & White (Gray Scale) Print Testing. If you have any images in color, please print your paper out in black and white to ensure that the tones and screens used in your images or figures reproduce well in black and white, too. However, your images will appear in full color in any distributed electronic proceedings and in the ACM digital library.

Resolution & CMYK. Figures, charts, and diagrams should use a vector image format (e.g. PDF, SVG). Raster images (e.g. photographs) should be at least 300 or 600 dpi for quality reproduction and saved as .tiff images (or other compatible formats that support print-quality resolution). When creating or revising your images for inclusion in the paper, we recommend choosing CMYK (and not RGB) as the color profile.

TIFF/PNG versus JPG (JPEG) image. For raster images (e.g. photos), TIFFs are preferred for press applications where quality takes priority over file size. When TIFFs are compressed (using LZW compression option when saving from Adobe Photoshop, for example), no image data is lost, thus ensuring maximum quality. A JPEG is a compressed image format designed to keep the file size small, which makes it ideal for use in web graphics. However, to achieve this, the JPEG format actually removes precision from the image. This is referred to as a lossy compression system. On a printout, the removed data tends to show up as blocky areas of a solid color, or ghosting near high-contrast changes. At higher print resolutions (a minimum of 200 dpi), there’s usually enough data in the JPEG file for the compression artefacts to be very noticeable. PNG files are also a good alternative as the format is also lossless.

Rules/Lines. Rules used in your graphs, tables or charts must be at least 0.5 point in stroke and black for quality reproduction. Finer lines and points than this will not reproduce well, even if you can see them on your laser printed hardcopy when checked — your laser printers will usually have a far lower resolution than the imagesetters that will be used.

Fonts. If your figure uses custom or any non-standard font, the characters may appear differently when printed in the proceedings. Remember to check your figure creation to ensure that all fonts are embedded or included in the figure correctly. Be sure that your images do not contain any Type 3 fonts.

Transparency. If a figure or image is assembled from multiple images, the images must be embedded, and layers be flattened or grouped together properly in the file. Transparency must be flattened.

Page Numbering, Headers, and Footers

Your final submission MUST NOT contain any footer at the bottom of each page (i.e., no page numbering), as submissions will be paginated in a determined order by the chairs and page numbers added to the PDF during the compiling, indexing, and pagination process.

The header must be set as per the ACM sigconf template - the top-left and top-right parts will contain (in alternance on each page) the conference name and information, the paper title, and/or the list of authors (or: the name of the first author followed by et al. if the string is too long). This should be automatically produced by the template.


It is the contact or submitting author’s responsibility to be sure that any funding or special contribution acknowledgements are included in the final version submitted as required by any research, financial, or other grants received (by using the “Acknowledgements” section before the References section). See page 4 of the ACM sample pdf.

Submitting the Required Files

When your final version is ready, you need to upload your zip file with PDF and source files using HotCrp. As an accepted author, you have access to the proceedings section of HotCrp.

You will see a confirmation screen after a successful upload to HotCrp. As well, a confirmation email will be sent to the contact’s email address entered on the submission page.

If changes are needed, then you will be contacted by one of the publication chairs. In that case, you will receive specific information about how to revise your submission to meet requirements, and a new deadline will be given to submit the corrected material. You are required by the chairs to adhere to this new deadline so the publication is not delayed. Failure to implement the requested changes could result in the paper being withdrawn.


If you still have questions or problems about the copyrights and formatting requirements, please email and with the conference name (Middleware 2021) in the subject line.


Events Dates
Abstract Submission May 15th May 22nd, 2021
Full Paper Submission May 22nd June 1st, 2021
Author Notification August 15th August 22nd, 2021
Revised Submissions September 15th, 2021
Notifications of Decisions of Revised Papers September 30th, 2021
Camera Ready October 18th October 25th, 2021


Events Dates
Workshop Proposal Submission May 21st, 2021
Industry Track Abstract Submission May 15th May 22nd, 2021
Industry Track Full Paper Submission May 22nd June 1st, 2021
Doctoral Symposium Submission September 22nd September 29th, 2021
Demo & Poster Submission October 1st, 2021


Events Dates
Abstract Submission November 20th, 2020
Full Paper Submission December 1st, 2020
Author Notification February 28th March 3rd, 2021
Revised Submissions April 2nd April 5th, 2021
Notifications of Decisions of Revised Papers April 30th May 20th, 2021
Camera Ready June 14th July 7th, 2021
Conference December 6th – 10th, 2021