Block Diagram Software Open Source. Any open source or paid affordable recommendations Windows Linux would be very welcome. Using Edge Diagrammer you can easily generate block diagrams flowcharts org.
Cant really tell from your question and your option list whether youre looking for block diagram software circuit diagram software or some integrated codeschematic editor. UMLet is a free open source state diagram maker software for Windows. Dia can read and write a number of different raster and vector image formats.
Dia Diagram Editor is free Open Source drawing software for Windows Mac OS X and Linux.
In this software you can create various types of diagrams like Flowcharts Block Diagrams UML Diagrams Network Diagrams Ladder Diagrams and more. This software is mainly used to perform prototyping of apps of both Android and iOS platforms. If you are looking for web-based diagramming software that is completely free to use you will love Drawio. Using this freeware you can quickly create state diagrams and variants of UML diagrams.