I have received a few Christmas cards which are in Powerpoint format. Is there an Ubuntu application that can open these files?
Ubuntu comes with LibreOffice, an office suite that replaces Microsoft Office. The LibreOffice equivalent to Microsoft PowerPoint is called Libreoffice Impress. You should be able to open your PPT or PPTX files by simply double-clicking the file.
I recommend you that WPS (Linux version) is great application, with word, present, slider. It also has other platform version -- windows, android, ios, and it's free for you. and i think better than office.
WPS office link It has lots of free online templates, which helps me a lot on my work.
To my experience, Libre Office has a lot of problems rendering properly ppt or pptx documents. The presentation is most of the time not matching at all the original document and the layout is often so messed up that it is almost impossible to read.
That has made me order at work a computer with Windows with the MS Office suite because I am unable to open documents (Excel, Word or PowerPoint) shared by colleagues to amend it.
And I have never been fully satisfied with MS Office suite over Wine as well.
That said, I do use Libre Office at home for most of my documents and it works very well if you stay in Libre Office.
Ubuntu comes with Libre Office which can though open up MS Powerpoint files but most of the time it render it messed up.
2nd Option could be MS Office over Wine.
3rd and my personal favorite option is installing Windows on a Virtual machine and installing required windows software over there. I personally use Oracle Virtual Box. A virtual machine basically will cater to all your needs for a particular Operation system.
4th Option - try to open it online with MS office online or Google docs. You will just need to register an account for free on http://outlook.com or https://onedrive.live.com and upload the powerpoint to onedrive and you will be able to just open it from there. This might have been the best option but you may not be willing to take confidential and official documents online.