What is the difference between TLXOS 4.8.x and 4.10.x? Which do I need?

Short answer: The releases are functionally near-identical, the main difference is that 4.8.x has older Citrix, VMware and RDP client versions; use 4.8.x only if you need to, and 4.10.x otherwise.

Long Answer:

We've been finding it increasingly difficult to reconcile the requirements of customers with old and unpatched servers who need era-appropriate client versions, and customers who need features or security fixes that are only available in the latest version clients.  Also, major changes such as changing the Debian version (as we recently did with TLXOS 4.9.x, based on Debian 10) inevitably results in additional bugs that affect some customers, and take some time for us to sort out.

For these reasons, starting with 4.8.0 we decided to do what many software providers are now doing and provide a "Long Term Stable" (LTS) alternative in addition to the latest release.  When TLXOS 5.0.0 (based on Debian 11) is released, 4.8.x will be discontinued and 4.10.x will become LTS.

TLXOS 4.8.x is more-or-less a continuation of TLXOS 4.6.1, still based on Debian 8 (Jessie) and using an uncompressed Ext2 root filesystem base layer rather than the compressed (and therefore slower) Reiser4 filesystem that TLXOS 4.7.1 and later use (we had no choice but to do this, as it was the only way that larger Debian 9/10 releases would fit in the available space).  It has a newer 5.4 kernel, and in the TLXOS RPi case supports Raspberry Pi 4 (which the equivalent Raspbian release never did).  However, included software is generally old as Debian 8 is now about 4 years old and three releases out of date.

4.8.x notably also has old versions of the Citrix (Receiver) and VMware (Horizon) clients.  4.8.x includes Citrix Receiver 13.7.0, which interoperates safely with old XenApp / XenDesktop servers that use obsolete SSL ciphers, and is also the last release with which ThinLinX's Pi H.264 hardware decoder plugin (based on example Citrix code from the Platform Optimization SDK) is known to work reliably.  The RPi edition of 4.8.x uses Horizon Client 4.5.0, which is the last version of Horizon Client for ARM Linux to support the PCoIP protocol (VMware dropped this in Horizon Client 4.6.0, on the ARM Linux platform only, for reasons they have never explained).  x86/x86_64 editions of TLXOS 4.8.x use Horizon Client either version 5.0.0 (last version to support the legacy client only) or 5.5.2 (last Horizon 7.x client) instead.

TLXOS 4.10.x are our latest releases, based on Debian 10 (Buster) rather than Debian 9 (Stretch), which 4.7.x used.  Except where there were known problems (e.g. x86 version of Horizon Client 5.4.1), 4.10.x includes the latest version of the major apps (Workspace App, Horizon Client, FreeRDP) that were available at the time of release.