Are there any alternatives to Microsoft Office Visio for Ubuntu?
I especially like yEd.
DIA is unusable in comparison. I still wonder how I managed to document my Bachelor's Thesis using it. Try aligning objects in DIA, try creating any diagram so that it doesn't look like it was done in 3 minutes.
And it's compatible with Windows and Macs too. Check it out
I've primarily used Inkscape. It's a very different UI, but it works well and it's a powerful tool. Output can (depending on input) look as professional as necessary.
In Inkscape, use the "Create diagram connector". It has the option to "Make connector avoid selected objects". If you draw a connector, then select the object you want to avoid, edit the connector and finally click the button to avoid that object, you can use smart connectors that will not overlap the different elements of your box. In practice, I find the easiest way to do this is to:
- Draw a connector
- Deselect the connector by clicking the object you want to avoid
- Hold SHIFT and double-click the connector you just drew
- Choose "Make connector avoid selected objects"
Also see this question and answers: Nice network diagram editor?
About the other recommendations
I haven't used it much yet, but yEd looks very good.
Alternatively, LibreOffice Draw is a popular piece of software, see other answers. One thing to note is that LibreOffice can now open Visio diagrams, and it lets you edit them. It works well for simple diagrams, not as well for very Visio-idiosyncrasy-intensive ones. It could still be usable with more effort, and in an environment with a lot of existing diagrams, this might be tolerable.
Many of the suggestions in other answers are good stand-ins for Visio for general diagramming. One gap I found was the lack of a decent set of network equipment symbols like those found in Visio. So I jumped in and built a set for OpenOffice/LibreOffice, now shipping in Fedora in the vrt-network-equipment package. It's also available to download here if you just want the OO/LibO extension.
Edit: Now also added to extensions.libreoffice.org and extensions.openoffice.org
I believe a solution that has been completely overlooked for far too long is Visual Paradigm. It's closed source, but it has a free community edition (non-commercial use) and is very stable and polished. Also, the UML only commercial license is only $99.
I would recommend Lucidchart as a robust alternative. As far as I know, it's the only Linux-compatible option that will import and export Visio documents and stencils.
Install Dia using the Ubuntu Software Centre.
I also like yEd very much: it has a straightforward approach to creating diagrams and lets you work efficiently after a very short while. The quality of the diagrams can be very high: there are advanced alignment functions, custom Icons can be imported (also from Visio) and there are various output formats available.
However, yEd requires an Oracle Sun Java VM, which is not standard e.g. in Ubuntu 11.10. A solution is given in http://yed.yworks.com/support/qa/17. The easiest solution for me was to download and extract the "Zipped yEd Jar" Download and call the Oracle Sun Java explicitely, like:
<path_to_Oracle_Java>/jre1.6.0_30/bin/java -jar <path_to_yEd>/yed-3.8/yed.jar
In addition to Dia, some good alternatives to Microsoft Visio are Libreoffice Draw, Calligra Flow and yED. There are some online alternatives but most of them have paid subscriptions. There is one online app which provides all the features for free though, its called draw.io. You can check it out!
Btw, you can follow this guide for more information.
I guess most web based solutions would match this answer. Of the web based solutions Creately offers a desktop solution that works on Linux. Although Flash haters might not like it.